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The organisms living around energized submarine power cables, pipe, and natural sea floor in the inshore waters of Southern California.

Abstract.--Between 1 February 2012 and 26 February 2014 using scuba, we surveyed the fishes, invertebrates, and macrophytes living on two energized submarine power cables, an adjacent pipe, and nearby natural habitat in southern California at bottom depths of 10-11 m and 13-14 m. Over the course of the study, average electromagnetic field (EMF) levels at the two cables (A and B) were statistically similar (Cable A = 73.0[micro]T, Cable B = 91.4[micro]T) and were much higher at these two cables than at either the pipe (average = 0.5[micro]T) or sand (0[micro]T). Overall, our study demonstrated that 1) the fish and invertebrate communities on cables, pipe, and natural habitat strongly overlapped and 2) there were no differences between the shallower and deeper fish and invertebrate communities. We saw no evidence that fishes or invertebrates are either preferentially attracted to, or repelled by, the EMF emitted by the cables. Any differences in the fish or invertebrate densities between cables, pipe, and natural habitat taxa were most likely due to the differences in the physical characteristics of these habitats. As with the fishes and invertebrates, macrophytes did not appear to be responding to the EMF emitted by the cables. Rather, it is likely that differences in the plant communities were driven by site depth and habitat type.

It is likely that for the foreseeable future, offshore renewable energy technologies will focus on the generation of electricity from renewable resources (e.g., wind and wave). Specifically in U.S. waters, there has been substantial interest in wind energy off the East Coast of the United States (Petruny-Parker et al. 2015; BOEM 2014), both wind and wave energy off the Pacific Coast (Boehlert et al. 2013), and harnessing tidal energy in Puget Sound (Thomson et al. 2012). These technologies harness energy from an array of individual devices and, through power cables, send electricity to shore via cables. These cables will transmit either alternating current or direct current, and, if the cable uses alternating current, this current will generate both electric and magnetic fields around these cables.

Research has shown that cartilaginous and some bony fishes, as well as at least some invertebrates, are sensitive to electromagnetic fields (EMF) and that these fields can alter the behavior of these organisms (Kalmijn 1982; Formicki et al. 2004; Tanski et al. 2005; and summarized in Normandeu et al. 2011). However, worldwide, only a few studies have been conducted to document the effects of EMF on marine organisms in situ (DONG Energy and Vattenfall 2006; Ohman et al. 2007; Westerberg and Lagenfelt 2008) or in a semi-artificially enclosed mesocosm (Gill et al. 2012). These studies have yielded either equivocal, or at best subtle, evidence of marine organisms responding to artificially induced EMF in a natural or semi-natural environment.

Submarine transmission cables that power offshore oil platforms in the Pacific Region provide an opportunity to examine potential responses of marine organisms to offshore renewable energy development (Fig. 1). We note that these power cables are industry standard, the type that will be used for connecting devices (35 KV) within renewable energy installations.

Specific objectives of this study were to determine:

1) If differences exist among fish, invertebrate, and plant communities associated with an energized cable habitat and those communities around a nearby pipe and soft seafloor lacking an energized cable.

2) If electro-sensitive species that are regionally important, such as sharks and rays, respond (via either attraction or repulsion) to the EMFs of an in situ power transmission cable.

3) The potential effectiveness of the commonly proposed mitigation of cable burial.

Materials and Methods

Our surveys were conducted by scuba off the coast of Las Flores Canyon, southern California (34[degrees]27.6'N, 120[degrees]02.7' W). In this area there are 1) three 20.32 cm (8") diameter submarine power cables (variously energized and unenergized) providing power to three offshore oil platforms and 2) a 30.48 cm (12") diameter pipe running from the platforms to shore (Fig. 1). The furthest distance between the outermost cable and the pipe is about 40m.

Prior to beginning the study, we found that sections of cable were both exposed and buried by natural disturbances and that EMF levels were lower on the sandy substrate directly over the buried cable than on the exposed cable. Thus to study the effect of the maximum EMF possible, we determined the survey would be conducted along unburied sections of the cable. Divers observed cables and pipeline for exposed continuous 30-m long sections, a standard transect length that we and other research groups have used for fish surveys in the region. We were able to find sufficient lengths of exposed energized cables (known as cables A and B) where fixed 30-m long transects could be set at two bottom depths. An unenergized cable (known as cable CI) was mostly buried, and we did not find any exposed 30-m lengths. Thus, for these surveys, we used the nearby exposed pipe as a surrogate for an unenergized cable. Divers surveyed fishes, invertebrates, and macrophytes along three habitats: an energized submarine power cable, a pipe, and a sandy, natural control area to the west of both cables and pipe (Fig. 2).

The experimental design was comprised of six fixed 30 m-long transects (treatments) of which one was installed in each of three habitats (along a cable, the pipe, and over sandy bottom) and in each of two depths (shallow. 10-11 m; and slightly deeper waters, 13-14 m depth). The end of the shallow transects and beginnings of the deep ones were separated by about 120 m. The beginning and ending of each transect in each habitat was marked by sand anchors as was each 5 m segment along each transect. Transects were 2 m wide, centered on the pipe or cable or an imaginary line between sand anchors that delineated the sandy control transect. Surveys of fishes, macroinvertebrates, and macrophytes were conducted every 2-4 weeks along the six transects during daylight hours by two divers.

At the beginning of the study we measured the EMF emitted by the power cables in our study area and found that two cables, A and B, were energized. We began our cable surveys on energized cable B. However, on 15 May 2013, we detected that cable B had become unenergized and we switched our surveys to energized cable A for the duration of the study. Importantly, both cables A and B had been energized for at least several years before cable B was switched off (D. Gilbert, pers. comm. to M. L.). The magnitude of EMF was measured at the beginning of each survey. A diver recorded readings from a detector placed directly against the cable, pipe, and sand. We used the Kruskal-Wallis one-way ANOVA on ranks to test for a difference in EMF field strength among habitats (Cable B, Cable A, Pipe, and natural habitat). The Wilcoxon test was used for nonparametric comparisons to identify where the EMF differed. The first diver surveyed all fishes encountered within 2 m above the substrate. Fish were identified to species, counted, and sized by eye to the nearest centimeter. A second diver followed and recorded the number of macrophytes in the 2 m swath centered over the cable and pipe or on the sand. The quantification of macrophytes was used to determine if these structure-forming organisms differentially modified the habitats. The second diver also recorded macroinvertebrates (i.e., cnidarians. mollusca, crustaceans, and echinoderms) encountered within the same 2-m-wide sampling area. Only individual invertebrates of at least 10 cm in any dimension were recorded.

We used the Kolmogorov Smirnov Two-Sample test to evaluate whether the size frequency distribution of all fishes differed between the cable, pipe, and natural habitats. Mean lengths among habitats were compared using Welch's test. The fish length observations from both cables A and B were combined for this analysis. We employed the permutational analysis of variance routine in PERMANOVA + for PRIMER (Anderson et al. 2008) to test the response (counts per transect) of the fish, invertebrate, and macrophyte communities, separately, to one or more of the factors: habitat (cable, pipe, natural), depth (shallow, deep), and time (survey). The dataset was divided into two periods; the first when cable B was surveyed and the second when cable A was surveyed. This was a reasonable approach given that the two cable environments were seen to be quite different in terms of the structure-forming macrophyte community that could possibly affect fish and mobile macroinvertebrate abundance. By analyzing data separately from each cable, we were able to determine whether, if a species was more abundant at either a cable or pipe, this pattern occurred at both energized cables (implying that EMF may have been responsible) or only at one of the cables (implying that some other environmental factor was responsible). The experimental design was a balanced, repeated measures 3-way analysis with fixed factors for each period of surveys. During each survey date, we sampled six different treatments (i.e., transects) without replication. The terms of the model were habitat, depth, time, habitat x depth, habitat x time, and depth x time. If the effect of habitat on the abundance of a species was significant (p<0.05), then posthoc PERMANOVA permutational t-tests were run for independent pairwise comparisons of abundance between cable, pipe, and natural habitat. P-values in the PERMANOVA routines were calculated using 9999 permutations that generated the test statistic distribution under a true null hypothesis based on the resemblance between the samples. The observations of fish and invertebrate counts per transect were log (x+1) transformed and the macrophyte dataset of counts per transect was square-root transformed before calculating the Bray-Curtis similarity coefficients that quantified the resemblance between multivariate transect samples. We used the PERMDISP routine in PRIMER to determine that either log(X+l) or square root transformations of the abundance data (count per transect) reduced the heterogeneity of dispersion of multivariate samples among the different experimental treatments. Similarly, we used the permutational analysis of variance routine to test the response (number per transect) of abundant individual species of fishes, invertebrates, and macrophytes to the same factors. The individual species data were transformed using either log(x+l) or square-root of x. The test statistic for individual species is based on a Euclidean distance matrix between samples (Anderson et al. 2008).

We used multidimensional scaling (M DS) ordination in PRIMER v6 (Clarke and Gorley, 2006) to visualize assemblage groupings of transect samples by habitat and depth. As a complement to the PERMANOVA analysis, we used a two-way crossed analysis of similarity (ANOSIM) in PRIMER to evaluate the degree of overlap in species composition across habitat and depth.

ANOSIM operates on the resemblance matrix to test the null hypothesis that there are no assemblage differences between pipe, cable, and natural habitats (factor A), allowing that there may be shallower/deeper differences (factor B), The ANOSIM sample test statistic, R, ranges from 0 (no difference between groups) to 1 (all dissimilarities between the groups are larger than any dissimilarities among samples with either group). A statistically significant (p<0.05) but negligibly small R-value close to 0 indicates that species composition differ between habitats, but strongly overlap.

Results

From 1 February 2012 to 26 February 2014, fishes and macrophyte surveys were conducted from the beginning to end of the study. Invertebrate surveys were conducted beginning on 22 June 2012 and continued until the end of the study. Surveys were conducted on a total of 38 days (Table 1). We note that the natural habitat was sand and eelgrass. Over the course of the study, average EMF levels at the two cables (A and B) were statistically similar (Cable A = 73.0[micro]T, Cable B = 91.4[micro]T) and were statistically higher at the two cables compared to the pipe (average = 0.5[micro]T) or sand (0[micro]T) (Fig. 3, Table 2). We note that previous studies have demonstrated that EMF levels reach background levels about one meter from this cable (Love et al. 2015, 2016).

We found that the fish community varied among the cables, pipe, and natural habitat; however, there was significant interaction between the effects of habitat and depth on assemblage structure (Table 3). Furthermore, the 3-dimensional MDS plots of the assemblages from transect samples demonstrates there is substantial overlap of the habitat groupings during the periods when Cable A (global R=0.043, p=0.007; Fig. 4) and Cable B were surveyed (global R=0.253, p=0.0001; Fig. 5). Depth-related differences appeared to be somewhat more pronounced when Cable A is compared to the pipe and natural habitat rather than in similar comparisons with Cable B (Fig. 4 and Fig 5, respectively).

We conducted a total of 38 days of fish surveys during three years. Over all habitats, 4465 individuals representing at least 44 species (summed from Tables 4, 5) were observed. Dominant species included adults of benthic-oriented, schooling taxa (i.e., Oxyjulis californica, Brachyistiusfremitus, Phanerodon furcatus, and Cymatogaster aggregate/), young-of-the-year (YOY) Sebastes that had newly settled out of the plankton (particularly Sebastes chrysomelas, S. carnatus, and S. atrovirens), and relatively solitary substrate-oriented species (i.e., Citharichthys spp.). Oxyjulis californica, Citharichthys spp., Phanerodon furcatus, YOY Sebastes, and B. fremitus were the most abundant taxa. Cables: At least 35 species and 1,661 individuals were observed over the energized cables. Oxyjulis californica, Citharichthys spp., B. frenata, P. furcatus, and YOY Sebastes were most abundant (Tables 4, 5). Pipe: The number of taxa (37) and individuals (1,712) were similar to those observed on the cables. Oxyjulis californica, YOY Sebastes, Sebastes miniatus YOY, Damalichthys vacca, Embiotoca jacksoni, and Citharichthys spp. were the most abundant taxa on the pipe (Tables 4, 5). Natural Habitat: Fewest species (25) and individuals (1,092) were observed over the natural habitat. Cymatogaster aggregata, Citharichthys spp., O. californica, YOY Sebastes jordani, P. furcatus, and Aulorhynchus flavidus were the most commonly observed species (Tables 4, 5).

Fish communities among all habitats were composed primarily of small-sized fishes with most being less than 20 cm long. The mean lengths of fishes (cables = 11.8 cm, pipe =11.4 cm. natural habitat = 9.7 cm) varied significantly among the three habitats (Welch's Test, F = 43.7, df = 2, p < 0.0001) as did the size distributions (Kolmogorov Smirnov Two-Sample Test: cables versus pipe, N = 3,484 K.S 0.053, p = <0.0001; cables versus natural habitat, N = 2,832 K.S 0.147, p = <0.0001; pipe versus natural habitat, N = 2,890 KS 0.117, p = <0.0001).

While the overall fish communities were similar among the three habitats, there were some fish species that were statistically more abundant over parts of either the cables or pipe (Table 3, Fig. 6). As examples, O. californica, Citharichthys spp., and E. jacksoni were all more abundant over Cable B than over the pipe (Table 3, Fig. 6). Similarly, B. fremitus, Sebastes paucispinis YOY, and Heterostichus rostratus were more abundant over Cable A compared to the pipe. However, with the exception of Citharichthys spp., none of these species were consistently more abundant at either the cablcs or the pipe or over both depths. Rather, in virtually all of these instances these differences were cither 1) limited to one of the two cables or 2) were not consistent between depths (Fig. 6). As an example, while O. californica was statistically more abundant at Cable B than at the pipe, it was less abundant at Cable A compared to the pipe. Similarly, Hypsunts caryi were more abundant on the inshore parts of the pipe compared to Cable A, but not on the offshore parts.

Invertebrates

As with the fish community, the invertebrate assemblages varied among the cables, pipe, and natural habitat with significant interaction between the effects of habitat and depth on assemblage structure (Table 6). The three-dimensional MDS plots of the assemblages from shallow and deep transect samples demonstrates substantial overlap of the habitat groupings during the periods when both cable B (global R=0.085, p=0.002; Fig. 7) and cable A were surveyed (global R=0.227, p=0.000l; Fig. 8). We conducted a total of 30 days of invertebrate surveys during three years. A total of 802 individuals were observed, comprising at least 19 species (Tables 7, 8). Patiria miniata, several species of Pisaster sea stars, Aplysia californica, Astropecten armatus, and Kelletia kelletii were observed most often. By group, sea stars were the most abundant, comprising 56.8% of all invertebrates observed. Cables-. We recorded 157 individuals of at least 15 species at the cable sites. P. miniata, Pisaster sea stars, and A. californica were most abundant (Tables 7, 8). Pipe: A total of 422 individual invertebrates, more than any other site, were observed at the pipe. However, 100 of these individuals were comprised of a one-time recorded aggregation of Strongylocentrotuspurpuratus. Like the cables, we recorded 15 species along the pipe (Tables 7, 8). Natural Habitat'. Patiria miniata and K. kelletii predominated in the natural habitat, where we recorded 223 individuals, of 13 species (Tables 7, 8). Again, consistent with what we observed for fish species, in comparing cables with the pipe, only one invertebrate species was consistently more abundant in either habitat: Pisaster spp. were more abundant over the pipe (Table 8, Fig. 9). Several other species, such as P. miniata, Parastichopus spp., A. californica, and Parastichopus spp. were not consistently more abundant on either cables or pipe.

Macrophytes

In contrast to the fish and invertebrate communities, the macrophyte assemblages were strikingly distinct from one another by habitat and depth. The interaction between these two effects on assemblage structure was significant (Table 9). The 3-dimensional MDS plots of the assemblages from shallow and deep transect samples demonstrates no overlap of the habitat groupings during the periods when Cable B (global R=0.998 p=0.0001; Fig. 10) and Cable A were surveyed (global R=0.993, p=0.0001; Fig. 11).

We conducted a total of 38 days of surveys during three years. A total of 76358 individual macrophytes (many likely observed repeatedly on sequential survey days) were tallied, comprising at least five species (Table 10). Overall, Zostera marina was most abundant (and found only on the natural habitat), followed by Pteiygophora californica, Cystoseira spp., Macrocystispyrifera, and Laminaria spp. Cables: Overall, Pteiygophora californica dominated the cable community, although Cystoseira spp. and Laminaria spp. were not uncommon (Table 10). However, note that P. californica was very abundant on Cable B (particularly shallower), but much less so on Cable A (Table 10). Zostera marina grew on the sand near the cable. Macrocystis pyrifera grew very sparsely on the shallower Cable B habitat, was more common on the shallower part of Cable A, and was essentially absent from the deeper cables (Fig. 12). Pipe: Cystoseira spp. was the most common macrophyte on the pipe (Table 10). Cystoseira spp. was about twice as abundant shallower than deeper while Laminaria spp. was almost absent from the shallower site and nearly as abundant as Cystoseira spp. deeper (Fig. 12). Relatively few P. californica were observed on the pipe and both M. pyrifera and Z marina were almost absent. Natural Habitat: Zostera marina was the only macrophyte growing on the sandy sea floor of the natural habitat (Table 10). It was dense at both the shallower and deeper sites (Fig. 12). As noted above, the macrophyte communities in the three habitats differed among each other and along the inshore and offshore transects. This was reflected in the distribution of all macrophyte species when comparing cable and pipe habitats (Table 10). Unlike with virtually all of the fish species and all of the invertebrate species, the differences in abundances were consistent between both cables and the pipe and at both depths (Fig. 12).

Discussion and Conclusions

We began this study with the understanding that if a species is attracted to an EMF we would expect to find that species in disproportionately larger numbers or densities around the energized cables compared to the pipe or natural habitat. Similarly, if a taxa is repelled by that EMF we would expect that species to be present less often or in lower densities at the cables. However, the presence or absence of an EMF is not the only habitat parameter influencing how an organism chooses its habitat. We acknowledge that in this study the cables and pipe differed not only in the production of an EMF but to some extent in the morphology of these habitats. In particular, the pipe was a slightly more complex structure. First, the pipe's diameter (30.48 cm) was somewhat greater than that of the two cables (20.32 cm), and while the cable was sometimes partially buried, the pipe was not. Thus for both reasons the pipe tended to present a somewhat higher profile. In addition, perhaps the greatest structural difference between the cables and pipe was the very high density, particularly on the shallower pipe, of Cystoceira sp., a brown alga that was essentially absent from the shallower cable. This alga forms a dense cover near the bottom and small fishes, particularly YOY Sebastes, will preferentially inhabit this complex substratum.

Algae also grew on the cable, particularly Macrocystis pyrifera on the shallower area of Cable A, and Laminaria sp. on the deeper portion of both cables. However, M. pyrifera does not form luxuriant bottom structures and the Laminaria stands, while present, did not present as dense a cover as the Cystoceira on the pipe. The sandy natural habitat was the least complex of all three; its two-dimensional aspect was only broken up by stands of Z. marina. At the start of the study Z. marina was only sporadically found and became more abundant over time.

Structural variability aside, the results of our study demonstrated that the fish and invertebrate assemblages of the three habitats were similar. Although a few species statistically varied in abundance between the cables and pipe, in no instance was a fish or invertebrate species extremely abundant at one of these two habitats and extremely rare or absent from the other. And although fishes were statistically larger at the pipe than at the cable or natural habitat, we argue that this difference (of less than one-half centimeter between pipe and cable and two centimeters between pipe and natural habitat) is not biologically meaningful.

Results of this study found no evidence that any species of fish or invertebrate was either preferentially attracted to, or repelled by, the EMF emitted by the cables. Any observed differences in the fish or invertebrate densities between cables, pipe, and natural habitat taxa are most likely due to the differences in the physical characteristics of these habitats. For example, the higher densities of YOY Sebastes and E. jacksoni at the pipe are most likely due to greater densities of understory algae, specifically Cvstoseira spp. In addition, the lower-relief cables, which were closer to the sandy sea floor, were a better habitat for soft-bottom dwelling sanddabs. Contrary to the fish and invertebrate assemblages, the plant communities on cables, pipe, and natural habitat were clearly different from one another. However, if cable EMF were responsible for these differences, we would expect to see similarities in plant communities between energized cables A and B and this was not the case. Rather, it appears that plant communities were driven by site depth (particularly among the algae) and habitat type (i.e., eelgrass).

We note that this study was not designed to directly determine the behavior of fishes and invertebrates when these organisms encounter an energized cable during, for instance, migrations. Rather, we observed the integration over time of myriads of such behaviors by many organisms. Understanding how individuals within a taxon relate to energized cables would have to involve either tracking (Westerberg and Lagenfelt 2008) or caging experiments (Love et al. 2015) or hybrids of the two (Gill et al. 2009).

In southern California, most along-shore migrations (as distinct from less synchronized movements) are conducted by such pelagic species as Prionace glauca and Sardinops sagax. The more substrate-associated shallower species (exemplified by the taxa that dominated our survey) tend to be either resident (i.e., Cephaloscyllium ventriosum, E. jacksoni), make seasonal shallower-deeper movements (H. caryi), or locally disperse as they mature (YOY Sebastes spp., C. aggregata). Given that the EMF emitted from the study cables is undetectable beginning at a distance of about one meter (Love et al. 2015, Love unpubl. data) it would be unlikely that pelagic and midwater species are affected by this field. In fact, the limited range of the EMF implies that only the movements of those species that live close to the bottom would be potentially impacted.

In our study area, some of the bottom-dwelling or bottom-oriented species most likely to respond to energized cables are the elasmobranchs: the sharks, skates, and rays. It is probable that all of these fishes can detect an EMF and this ability appears to be used for a number of behaviors including migration and food detection (Kalmijn 1971, Tricas 1982, Klimley et al. 2005). Moreover, while the actual sensitivity to an EMF is known for only a few elasmobranch species, we note that at least two Atlantic species, Carcharhinus plumbeus and Sphyrna lexvini, are able to detect an EMF in the 25-100pT range (Meyer et al. 2005); this is within the range generated by the current surveys' energized cables.

The shallower habitats of southern California, and specifically this study site, harbor a rich diversity of elasmobranchs (Love 2011). These include both mobile taxa (e.g., Triakis semifasciata and Mustelus spp.) and more sedentary species (Rhinobatosproductus, Platyrhinoidis triseriata, and Squatina californica). Given this diversity, it is interesting to note that over the course of this study we observed only two elasmobranch individuals, C. ventriosum near the pipe and Urobatis halleri near Cable B. It might be argued that the chances of seeing individuals of the more motile species would be small on any given day; although these chances would likely be increased if the animals were attracted to the cables. However, if the more sedentary species were similarly attracted, one might expect to have encountered them. And again, the absence of these animals from the cable is likely not because the EMF generated is below their sensory threshold. Rather, the data strongly imply that of the electro-sensitive species in the study area, at least the elasmobranchs are not attracted to the energized cables.

Our findings are particularly important because, worldwide, the small number of field or semi-field studies that have been conducted on how fishes respond to energized power cables have found either little or no response (Westerberg and Lagenfelt 2008, DONG Energy and Vattenfall A/S 2006, Love et al. 2015, present study) or, arguably, an equivocal one (Gill et al. 2009). One possible explanation is that marine organisms respond to human-made EMF differently from those produced in nature. Recent studies demonstrate that human-made EMF is inherently different from naturally produced EMF, with naturally produced EMF being polarized and consequently more biologically active (Panagopoulos et al. 2015). Thus, it is possible that electro-sensitive organisms are able to differentiate between the two types and therefore respond differently to each of these stimuli.

Regarding the specific objectives of this study:

1) Differences exist among fish and invertebrate communities associated with energized and unenergized cable habitat and those communities in soft seafloor habitats lacking cables.

We did not find any biologically significant differences among fish and invertebrate communities between energized cables, pipe, and natural habitat. In particular, only three species of fish showed statistically significant, but slight, differences in densities between the cables and pipe. Plant communities did differ among habitats and within habitats between depths. These differences were almost certainly structure and depth, rather than EMF, related.

2) Electro-sensitive species that are regionally important, such as sharks and rays, respond (via either attraction or repulsion) to the EMEs of an in situ power transmission cable.

We observed two elasmobranch individuals, C. ventriosum near the pipe and Urobatis halleri near one of the two energized cables, during the course of this study. Thus, it would appear that the EMFs generated by energized cables are either unimportant to these organisms or that at least other environmental factors take precedence.

3) The potential effectiveness of the commonly proposed mitigation of cable burial.

Given the rapidity with which the EMF produced by the energized cables diminishes and the lack of response to that EMF by the shallower fish and invertebrates, cable burial would not appear necessary strictly for biological reasons. In this and similar cases, cable burial, at sufficient depth, would be an adequate tool to prevent EMF emissions from being present at the seafloor.

Acknowledgements

We thank Donald Macaskill, Jorge Gross, Frank Hurd, Jacob Eurich, Donna Schroeder, and Christopher Teague for their field assistance. This work was funded by the Bureau of Ocean Energy Management (BOEM), BOEM Cooperative Agreement No. Ml 1AC00008.

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Petruny-Parker, M., A. Malek, M. Long, D. Spencer, F. Mattera, E. Hasbrouck, J. Scotti, K. Gerbino, and J. Wilson. 2015. Identifying Information Needs and Approaches for Assessing Potential Impacts of Offshore Wind Farm Development on Fisheries Resources in the Northeast Region. US Dept. of the Interior, Bureau of Ocean Energy Management, Office of Renewable Energy Programs, Herndon, VA. OCS Study BOEM 2015-037.

Tanski, A., K. Formicki, P. Smietana, M. Sadowski, and A. Winnicki. 2005. Sheltering behaviour of spinycheek crayfish (Orconectes limosus) in the presence of an artificial magnetic field. Bull. Fran. Peche Pisciculture 376:787-793.

Thomson, J., B. Polagye, V. Durgesh, and M.C. Richmond. 2012. Measurements of turbulence at two tidal energy sites in Puget Sound, WA. IEEE J. Ocean Eng. 37:363-374.

Tricas, T. 1982. Bioelectric-mediated predation by swell sharks, Cephaloscyllium ventriosum. Copeia (4):948-952.

Westerberg, H. and I. Lagenfelt. 2008. Sub-sea power cables and the migration behaviour of the European eel. Fish. Manage. Ecol. 15:369-375.

Milton S. Love, (1) * Mary M. Nishimoto, (1) Scott Clark, (1) Merit McCrea, (1) and Ann Scarborough Bull (2)

(1) Marine Science Institute, University of California, Santa Barbara, CA 93106

(2) Bureau of Offshore Energy Management, 770 Paseo Camarillo, Camarillo, CA 93010

* Corresponding author: love@lifesci.ucsb.edu

Caption: Fig. 1. Location of the energized and unenergized submarine power cables and pipe in the study area.

Caption: Fig. 2. Schematic illustration of cables, pipe, and natural habitat surveyed by scuba, 1 February 2012-26 February 2014. Cables A and B were energized and were used in this study. The nearshore section of Cable C has been removed. Cable [C.sup.1] was unenergized and was not used in this study as it was mostly buried in the sea floor. Distance between cables, pipe, and natural habitat not drawn to scale.

Caption: Fig. 3. Electromagnetic field levels measured on cables, pipe, and natural habitat surveyed from 1 February 2012-26 February 2014. Vertical bars represent standard errors.

Caption: Fig. 4. A 3-d multiple dimensional scaling model comparing the fish assemblages from shallower and deepertransects in Cable B, pipe, and natural habitat.

Caption: Fig. 5. A 3-d multiple dimensional scaling model comparing the fish assemblages from shallower and deeper transects in Cable A, pipe, and natural habitat.

Caption: Fig. 6. Mean fish species densities found at the shallower and deeper sites at the three habitats. Data is divided into two periods when 1) Cable B was surveyed and 2) when Cable A was surveyed. KGB = young-of-the-year Sebastes atrovirens, S. carnatus, S. chrvsomelas, and 5. caurinus.

Caption: Fig. 7. A 3-d multiple dimensional sealing model comparing the invertebrate assemblages from shallower and deeper transects in Cable B, pipe, and natural habitat.

Caption: Fig. 8. A 3-d multiple dimensional scaling model comparing the invertebrate assemblages from shallower and deeper transects in Cable A, pipe, and natural habitat.

Caption: Fig. 9. Mean invertebrate species densities found at the shallower and deeper sites at the three habitats. Data is divided into two periods when 1) Cable B was surveyed and 2) when Cable A was surveyed.

Caption: Fig. 10. A 2-d multiple dimensional scaling model comparing the macrophyte assemblages from shallower and deeper transects in Cable B, pipe, and natural habitat.

Caption: Fig. 11. A 2-d multiple dimensional scaling model comparing the macrophyte assemblages from shallower and deeper transects in Cable A, pipe, and natural habitat.

Caption: Fig. 12. Mean macrophyte species densities found at the shallower and deeper sites at the three habitats. Data is divided into two periods when 1) Cable B was surveyed and 2) when Cable A was surveyed.
Table 1. All dates of surveys on energized cables, pipe,
and natural habitat. Fishes and plants were surveyed on all
dates; invertebrates were surveyed from 22 June 2012 to
26 February 2014. Surveys were conducted on energized
Cable B from 1 February 2012 to 15 May 2013 and on
energized Cable A from 14 June 2013 to 26 February 2014.

2012
1 Feb.    22 Feb.   8 Mar.    27 Mar     12 Apr.
13 July   25 July   10 Aug.   22 Aug     11 Sept.

2013
8 Jan.    5 Feb.    28 Feb.   12 March   3 Apr.
9 July    16 Aug.   30 Aug.   13 Sept.   30 Sept.
31 Dec.

2014
15 Jan.   12 Feb.   26 Feb.

2012
1 Feb.    24 Apr.   9 May    8 June    22 June
13 July   2 Nov.    7 Dec.

2013
8 Jan.    24 Apr.   3 May    15 May    14 June
9 July    18 Oct.   8 Nov.   20 Nov.   6 Dec.
31 Dec.

2014
15 Jan.

Table 2. Wilcoxon test values comparing EMF field strengths
of two energized cables, pipe, and natural habitat, 2012-2014.
NH = natural habitat.

Site      Site         Mean      Standard     Z     p-value
                    Difference    Error

Cable B   Cable A      5.95        4.15     1.43     0.15
NH        Cable A     -32.46       4.40     -7.38   <.0001
Pipe      Cable A     -34.46       5.30     -6.50   <.0001
Pipe      Cable B     -36.39       5.30     -6.87   <.0001
NH        Cable B     -36.97       4.67     -7.92   <.0001
NH        Pipe        -43.74       5.34     -8.18   <.0001

Table 3. P-values from the repeated measures PERMANOVA
testing the effects of habitat (HA), depth (IN), and sampling
date (DA) on fish community structure and density of individual

taxa and from PERMANOVA pairwise tests for differences between
habitats for the periods when Cables B and A were surveyed.
YOY = young-of-the-year. Species selected were those that
comprised at least 1% of all fishes observed. Statistically
significant results are underlined.

Cable B                       HA        IN        DA

Fish community              0.0001    0.0287    0.0001
Taxon:
Oxvjulis californica        0.0347    0.9836    0.0001
Citharichthys spp.          0.0007    0.4798    0.0007
Phanerodon furcatus         0.1716    0.1071    0.0313
Cvmatogaster aggregata      0.1005    0.6411    0.0001
KGB YOY (1)                 0.0038    0.0341    0.0006
Brachvistius fremitus       0.3762    0.1600    0.4938
Sebastes miniatus YOY       0.0916    0.0001    0.0001
Embiotoca jacksoni          0.0033    0.0916    0.0162
Aulorhynchus flavidus       0.4649    0.3638    0.4685
Hvpsurus carvi              0.4824    0.0381    0.0037
Damalichthvs vacca          0.0573    0.1179    0.4520
Sebastes caurinus           0.4054    0.3437    0.3529
Sebastes paitcispinis YOY   0.1283    0.4334    0.0667
Sebastes                    0.3805    0.2238    0.0121
  serranoidestSebastes
  flavidus YOY
Heterostiehus rostratus     0.0318    0.2473    0.0162

Cable B                      HAxIN     HAxDA     INxDA

Fish community              0.0127    0.5245    0.1356
Taxon:
Oxvjulis californica        0.0144    0.8534    0.7389
Citharichthys spp.          0.0325    0.8485    0.0311
Phanerodon furcatus         0.1453    0.7047    0.9496
Cvmatogaster aggregata      0.8181    0.0014    0.9112
KGB YOY (1)                 0.2227    0.1552    0.0718
Brachvistius fremitus       0.4066    0.5033    0.5837
Sebastes miniatus YOY       0.0121    0.1177    0.0001
Embiotoca jacksoni          0.8015    0.0412    0.3053
Aulorhynchus flavidus       0.1924    0.4316    0.4712
Hvpsurus carvi              0.1316    0.7651    0.1409
Damalichthvs vacca          0.0224    0.4984    0.4779
Sebastes caurinus           0.4371    0.511 1   0.4941
Sebastes paitcispinis YOY   0.6773    0.9587    0.1426
Sebastes                    0.9045    0.8630    0.0053
  serranoidestSebastes
  flavidus YOY
Heterostiehus rostratus     0.0148    0.6152    0.9351

Cable B                     Cable,    Cable,     Pipe,
                             pipe     natural   natural

Fish community              0.0016    0.0051    0.0002
Taxon:
Oxvjulis californica        0.0470    0.0546    0.9695
Citharichthys spp.          0.0001    0.1 107   0.0494
Phanerodon furcatus
Cvmatogaster aggregata
KGB YOY (1)                 0.5834    0.0008    0.0092
Brachvistius fremitus
Sebastes miniatus YOY
Embiotoca jacksoni          0.0473    0.0661    0.0077
Aulorhynchus flavidus
Hvpsurus carvi
Damalichthvs vacca
Sebastes caurinus
Sebastes paitcispinis YOY
Sebastes
  serranoidestSebastes
  flavidus YOY
Heterostiehus rostratus     0.5088    0.0085    0.0092

Cable B                       HA        IN        DA

Fish community              0.0001    0.0001    0.0001
Taxon:
Oxvjulis californica        0.0027    0.0161    0.0001
Citharichthys spp.          0.0022    0.0001    0.1479
Phanerodon furcatus         0.0199    0.1778    0.0126
Shiner perch                0.0406    0.5422    0.0291
KGB YOY (1)                 0.0001    0.0067    0.0001
Brachyistius frenatus       0.0166    0.0096    0.2912
Sebastes miniatus YOY       0.3610    0.0793    0.0660
Embiotoca jacksoni          0.0001    0.0001    0.0062
Aulorhynchus flavidus       0.4554    0.7378    0.3142
Hypsurus caiyi              0.0004    0.0006    0.0314
Damalichthys vacca          0.0691    0.0012    0.4786
Sebastes caurinus           0.0004    0.2144    0.0008
Sebastes paucispinis YOY    0.0438    0.8801    0.8572
Sebastes                    0.4668    0.9484    0.1391
  serranoides!Sebastes
  flavidus YOY
Heterostichus rostratus     0.0050    0.0306    0.1265

Cable B                      HAxIN     HAxDA     INxDA

Fish community              0.0002    0.0085    0.0001
Taxon:
Oxvjulis californica        0.0356    0.5450    0.0002
Citharichthys spp.          0.1831    0.5405    0.3673
Phanerodon furcatus         0.2533    0.1704    0.0041
Shiner perch                0.6874    0.0094    0.4952
KGB YOY (1)                 0.0466    0.0028    0.1993
Brachyistius frenatus       0.0111    0.5226    0.2729
Sebastes miniatus YOY       0.0805    0.1797    0.0528
Embiotoca jacksoni          0.0002    0.4926    0.0375
Aulorhynchus flavidus       0.8891    0.9822    0.8205
Hypsurus caiyi              0.0093    0.8955    0.2189
Damalichthys vacca          0.3506    0.4163    0.2530
Sebastes caurinus           0.3915    0.0298    0.3777
Sebastes paucispinis YOY    0.7147    0.7701    0.5658
Sebastes                    0.3712    0.9601    0.7776
  serranoides!Sebastes
  flavidus YOY
Heterostichus rostratus     0.0145    0.1581    0.0474

Cable B                     Cable,    Cable,     Pipe,
                             pipe     natural   natural

Fish community              0.0004    0.0003    0.0001
Taxon:
Oxvjulis californica        0.0210    0.0949    0.0105
Citharichthys spp.          0.0068    0.8271    0.0025
Phanerodon furcatus         0.0516    0.0108    0.2880
Shiner perch                0.3513    0.0165    0.1574
KGB YOY (1)                 0.0001    0.0002    0.0001
Brachyistius frenatus       0.0409    0.0344    0.3601
Sebastes miniatus YOY
Embiotoca jacksoni          0.1134    0.0003    0.0001
Aulorhynchus flavidus
Hypsurus caiyi              0.0376    0.0429    0.0001
Damalichthys vacca
Sebastes caurinus           0.1484    0.0003    0.0020
Sebastes paucispinis YOY    0.0480    0.1252    0.3454
Sebastes
  serranoides!Sebastes
  flavidus YOY
Heterostichus rostratus     0.031 1   0.0070    0.2236

(1) Sebastes atrovirens, S. caurinus, S. carnatus, S. chrysomelas

Table 4. Total count across all habitats and mean (SE)
number of fishes per transect in each habitat during
period when Cable B was surveyed, 1 February 2012-15 May 2013.
Two transects, shallow and deep, were surveyed in each habitat
on 23 sampling dates. Number of transect surveys in each habitat,
n = 46. YOY = young-of-the-year.

                                       All          Cable B
                                     habitats

Scientific name                       Count      Mean     (SE)

Oxyjulis californica                    460      5.35    (1.75)
Citharichthys spp.                      496      5.48    (1.19)
Phanerodon furcatus                     111      0.78    (0.48)
Cymatogaster aggregata                  278      1.13    (0.69)
Sebastes atrovirens, S. caurinus,       180      1.72    (0.58)
  S. carnatus, or 5. chrysomelas
  YOY
Brachyistius fremitus                    75      0.39    (0.15)
Sebastes miniatus YOY                   228      1.13    (0.57)
Sebastes jordani YOY                    190      0.43    (0.43)
Embiotocajacksoni                        78      0.39    (0.13)
Aulorhynchus flavidus                   158      0.72    (0.67)
Hypsurus carvi                           26      0.15    (0.07)
Damalichthys vacca                      119      0.02    (0.02)
Sebastes caurinus                        52      0.74    (0.41)
Sebastes paucispinis                     81      0.28    (0.20)
Sebastes serranoides or S.               40      0.13    (0.08)
  flavidus YOY
Heterostichus rostratus                  23      0.30    (0.15)
Sebastes semicinctus                     29      0.22    (0.18)
Synodus lucioceps                         1      0.00    (0.00)
Oxylebius pictus                         12      0.09    (0.04)
Sebastes mystinus                         1      0.00    (0.00)
Sebastes auriculatus                     17      0.00    (0.00)
Scorpaenichthys mannoratus                7      0.07    (0.04)
Hexagrammos decagrammus                   2      0.00    (0.00)
Pleuronichthys coenosus                   6      0.04    (0.03)
Gibbonsia spp.                            2      0.02    (0.02)
Sebastes dalli                            5      0.04    (0.03)
Paralabrax clathratus                     1      0.02    (0.02)
Unidentified Cottidae                     3      0.00    (0.00)
Leiocottus hirundo                        4      0.00    (0.00)
Neoclinus blanchardi                      1      0.02    (0.02)
Ophiodon elongatus                        5      0.04    (0.03)
Paralichthys californicus                 1      0.00    (0.00)
Sebastes atrovirens                       3      0.02    (0.02)
Unidentified fishes                       3      0.07    (0.05)
Gibbonsia spp.                            2      0.00    (0.00)
Sebastes carnatus                         1      0.02    (0.02)
Paralabrax nebulifer                      1      0.02    (0.02)
Pleuronichthys decurrens                  1      0.00    (0.00)
Porichthvs spp.                           1      0.00    (0.00)
Rathbunella spp.                          1      0.00    (0.00)
Sebastes rastrelliger                     1      0.00    (0.00)
Urobatis halleri                          1      0.02    (0.02)
All fishes                             2707     19.93    (3.91)

                                         Pipe

Scientific name                      Mean     (SE)

Oxyjulis californica                 2.78    (1.63)
Citharichthys spp.                   1.87    (0.48)
Phanerodon furcatus                  0.20    (0.09)
Cymatogaster aggregata               0.09    (0.06)
Sebastes atrovirens, S. caurinus,    2.11    (0.83)
  S. carnatus, or 5. chrysomelas
  YOY
Brachyistius fremitus                1.22    (1.02)
Sebastes miniatus YOY                3.30    (1.85)
Sebastes jordani YOY                 1.09    (1.09)
Embiotocajacksoni                    1.20    (0.46)
Aulorhynchus flavidus                0.41    (0.18)
Hypsurus carvi                       0.28    (0.12)
Damalichthys vacca                   2.54    (1.94)
Sebastes caurinus                    0.33    (0.14)
Sebastes paucispinis                 1.46    (0.88)
Sebastes serranoides or S.           0.67    (0.57)
  flavidus YOY
Heterostichus rostratus              0.20    (0.11)
Sebastes semicinctus                 0.41    (0.39)
Synodus lucioceps                    0.00    (0.00)
Oxylebius pictus                     0.17    (0.06)
Sebastes mystinus                    0.02    (0.02)
Sebastes auriculatus                 0.37    (0.35)
Scorpaenichthys mannoratus           0.09    (0.04)
Hexagrammos decagrammus              0.04    (0.03)
Pleuronichthys coenosus              0.02    (0.02)
Gibbonsia spp.                       0.02    (0.02)
Sebastes dalli                       0.07    (0.07)
Paralabrax clathratus                0.00    (0.00)
Unidentified Cottidae                0.07    (0.04)
Leiocottus hirundo                   0.07    (0.05)
Neoclinus blanchardi                 0.00    (0.00)
Ophiodon elongatus                   0.00    (0.00)
Paralichthys californicus            0.00    (0.00)
Sebastes atrovirens                  0.04    (0.03)
Unidentified fishes                  0.00    (0.00)
Gibbonsia spp.                       0.04    (0.03)
Sebastes carnatus                    0.00    (0.00)
Paralabrax nebulifer                 0.00    (0.00)
Pleuronichthys decurrens             0.00    (0.00)
Porichthvs spp.                      0.02    (0.02)
Rathbunella spp.                     0.02    (0.02)
Sebastes rastrelliger                0.02    (0.02)
Urobatis halleri                     0.00    (0.00)
All fishes                          22.24    (5.56)

                                        Natural

Scientific name                      Mean     (SE)

Oxyjulis californica                 1.87    (0.95)
Citharichthys spp.                   3.43    (0.69)
Phanerodon furcatus                  1.43    (0.83)
Cymatogaster aggregata               4.83    (4.35)
Sebastes atrovirens, S. caurinus,    0.09    (0.04)
  S. carnatus, or 5. chrysomelas
  YOY
Brachyistius fremitus                0.02    (0.02)
Sebastes miniatus YOY                0.52    (0.30)
Sebastes jordani YOY                 2.61    (2.61)
Embiotocajacksoni                    0.11    (0.09)
Aulorhynchus flavidus                2.30    (1.82)
Hypsurus carvi                       0.13    (0.07)
Damalichthys vacca                   0.02    (0.02)
Sebastes caurinus                    0.07    (0.04)
Sebastes paucispinis                 0.02    (0.02)
Sebastes serranoides or S.           0.07    (0.04)
  flavidus YOY
Heterostichus rostratus              0.00    (0.00)
Sebastes semicinctus                 0.00    (0.00)
Synodus lucioceps                    0.02    (0.02)
Oxylebius pictus                     0.00    (0.00)
Sebastes mystinus                    0.00    (0.00)
Sebastes auriculatus                 0.00    (0.00)
Scorpaenichthys mannoratus           0.00    (0.00)
Hexagrammos decagrammus              0.00    (0.00)
Pleuronichthys coenosus              0.07    (0.05)
Gibbonsia spp.                       0.00    (0.00)
Sebastes dalli                       0.00    (0.00)
Paralabrax clathratus                0.00    (0.00)
Unidentified Cottidae                0.00    (0.00)
Leiocottus hirundo                   0.02    (0.02)
Neoclinus blanchardi                 0.00    (0.00)
Ophiodon elongatus                   0.07    (0.05)
Paralichthys californicus            0.02    (0.02)
Sebastes atrovirens                  0.00    (0.00)
Unidentified fishes                  0.00    (0.00)
Gibbonsia spp.                       0.00    (0.00)
Sebastes carnatus                    0.00    (0.00)
Paralabrax nebulifer                 0.00    (0.00)
Pleuronichthys decurrens             0.02    (0.02)
Porichthvs spp.                      0.00    (0.00)
Rathbunella spp.                     0.00    (0.00)
Sebastes rastrelliger                0.00    (0.00)
Urobatis halleri                     0.00    (0.00)
All fishes                          17.76    (5.85)

Table 5. Total count across all habitats and mean (SE)
number of fishes per transect in each habitat during period
when Cable A was surveyed, 14 June 2013-26 February 2014. Two
transects, shallow and deep, were surveyed in each habitat on
14 sampling dates. Number of transect surveys in each habitat,
n = 28. YOY = young-of-the-year.

                                    All          Cable A
                                  habitats

Scientific name                    Count      Mean      (SE)

Oxvjulis californica                414       3.96     (1.14)
Citharichthvs spp.                  140       2.14     (0.50)
Phanerodon furcatus                 241       4.29     (1.29)
Cymatogaster aggregate!              56       0.00     (0.00)
Sebastes atrovirens, S.             151       1.79     (0.54)
  caurinus, S. earnatus. or S.
  chrysomelas YOY
Brachvistius frenatus               199       6.18     (2.76)
Sebastes miniatus YOY                27       0.36     (0.15)
Sebastes jordani YOY                  0       0.00     (0.00)
Embiotoca jacksoni                  104       1.68     (0.70)
Aulorhynchus flavidus                 7       0.07     (0.05)
Hypsurus caryi                      123       1.29     (0.30)
Damalichthys vacca                   23       0.29     (0.15)
Sebastes caurinus                    54       0.71     (0.27)
Sebastes paucispinis                 18       0.54     (0.24)
Sebastes serranoides or              32       0.43     (0.14)
  Sebastes flavidus YOY
Heterostichus rostratus              22       0.54     (0.18)
Sebastes semicinctus                 15       0.21     (0.15)
Svnodus lucioceps                    26       0.79     (0.68)
Oxylebius pictus                     13       0.29     (0.13)
Sebastes mystinus                    19       0.36     (0.19)
Sebastes auriculatus                  2       0.04     (0.04)
Scorpaenichthys marmoratus            7       0.00     (0.00)
Hexagrammos deeagrammus              10       0.07     (0.05)
Pleuronichthys coenosus               6       0.14     (0.08)
Gibbonsia spp.                        8       0.04     (0.04)
Sebastes dalli                        5       0.14     (0.14)
Paralabrax clathratus                 6       0.14     (0.14)
Coryphopterus nicholsii               6       0.00     (0.00)
Unidentified Cottidae                 3       0.00     (0.00)
Leiocottus hirundo                    2       0.04     (0.04)
Neoclinus blanchardi                  4       0.07     (0.05)
Paralichthys californicus             4       0.00     (0.00)
Sebastes atrovirens                   1       0.04     (0.04)
Syngnathus spp.                       3       0.04     (0.04)
Sebastes earnatus                     1       0.00     (0.00)
Cephaloscyllium ventriosum            1       0.00     (0.00)
Halichoeres semicinctus               1       0.04     (0.04)
Heterodontus Jrancisci                1       0.00     (0.00)
Myliobatis californica                1       0.00     (0.00)
Phanerodon atripes                    1       0.00     (0.00)
Unidentified Embiotocidae             1       0.00     (0.00)
All fishes                         1758      26.86     (4.05)

                                       Pipe

Scientific name                    Mean     (SE)

Oxvjulis californica               8.46    (2.13)
Citharichthvs spp.                 0.71    (0.20)
Phanerodon furcatus                2.75    (1.19)
Cymatogaster aggregate!            0.29    (0.29)
Sebastes atrovirens, S.            3.50    (0.81)
  caurinus, S. earnatus. or S.
  chrysomelas YOY
Brachvistius frenatus              0.79    (0.64)
Sebastes miniatus YOY              0.43    (0.17)
Sebastes jordani YOY               0.00    (0.00)
Embiotoca jacksoni                 2.00    (0.48)
Aulorhynchus flavidus              0.04    (0.04)
Hypsurus caryi                     2.61    (0.60)
Damalichthys vacca                 0.46    (0.17)
Sebastes caurinus                  1.21    (0.42)
Sebastes paucispinis               0.00    (0.00)
Sebastes serranoides or            0.43    (0.26)
  Sebastes flavidus YOY
Heterostichus rostratus            0.18    (0.07)
Sebastes semicinctus               0.32    (0.25)
Svnodus lucioceps                  0.00    (0.00)
Oxylebius pictus                   0.18    (0.09)
Sebastes mystinus                  0.32    (0.22)
Sebastes auriculatus               0.04    (0.04)
Scorpaenichthys marmoratus         0.21    (0.08)
Hexagrammos deeagrammus            0.29    (0.16)
Pleuronichthys coenosus            0.04    (0.04)
Gibbonsia spp.                     0.25    (0.08)
Sebastes dalli                     0.04    (0.04)
Paralabrax clathratus              0.07    (0.05)
Coryphopterus nicholsii            0.21    (0.12)
Unidentified Cottidae              0.11    (0.08)
Leiocottus hirundo                 0.04    (0.04)
Neoclinus blanchardi               0.07    (0.05)
Paralichthys californicus          0.07    (0.05)
Sebastes atrovirens                0.00    (0.00)
Syngnathus spp.                    0.04    (0.04)
Sebastes earnatus                  0.04    (0.04)
Cephaloscyllium ventriosum         0.04    (0.04)
Halichoeres semicinctus            0.00    (0.00)
Heterodontus Jrancisci             0.04    (0.04)
Myliobatis californica             0.00    (0.00)
Phanerodon atripes                 0.00    (0.00)
Unidentified Embiotocidae          0.00    (0.00)
All fishes                        26.68    (3.47)

                                      Natural

Scientific name                    Mean     (SE)

Oxvjulis californica               2.36    (0.56)
Citharichthvs spp.                 2.14    (0.48)
Phanerodon furcatus                1.57    (0.65)
Cymatogaster aggregate!            1.71    (1.43)
Sebastes atrovirens, S.            0.11    (0.06)
  caurinus, S. earnatus. or S.
  chrysomelas YOY
Brachvistius frenatus              0.14    (0.11)
Sebastes miniatus YOY              0.18    (0.15)
Sebastes jordani YOY               0.00    (0.00)
Embiotoca jacksoni                 0.04    (0.04)
Aulorhynchus flavidus              0.14    (0.07)
Hypsurus caryi                     0.50    (0.23)
Damalichthys vacca                 0.07    (0.05)
Sebastes caurinus                  0.00    (0.00)
Sebastes paucispinis               0.11    (0.11)
Sebastes serranoides or            0.29    (0.25)
  Sebastes flavidus YOY
Heterostichus rostratus            0.07    (0.05)
Sebastes semicinctus               0.00    (0.00)
Svnodus lucioceps                  0.14    (0.14)
Oxylebius pictus                   0.00    (0.00)
Sebastes mystinus                  0.00    (0.00)
Sebastes auriculatus               0.00    (0.00)
Scorpaenichthys marmoratus         0.04    (0.04)
Hexagrammos deeagrammus            0.00    (0.00)
Pleuronichthys coenosus            0.04    (0.04)
Gibbonsia spp.                     0.00    (0.00)
Sebastes dalli                     0.00    (0.00)
Paralabrax clathratus              0.00    (0.00)
Coryphopterus nicholsii            0.00    (0.00)
Unidentified Cottidae              0.00    (0.00)
Leiocottus hirundo                 0.00    (0.00)
Neoclinus blanchardi               0.00    (0.00)
Paralichthys californicus          0.07    (0.07)
Sebastes atrovirens                0.00    (0.00)
Syngnathus spp.                    0.04    (0.04)
Sebastes earnatus                  0.00    (0.00)
Cephaloscyllium ventriosum         0.00    (0.00)
Halichoeres semicinctus            0.00    (0.00)
Heterodontus Jrancisci             0.00    (0.00)
Myliobatis californica             0.04    (0.04)
Phanerodon atripes                 0.04    (0.04)
Unidentified Embiotocidae          0.04    (0.04)
All fishes                         9.89    (2.15)

Table 6. P-values from the repeated measures PERMANOVA
testing the effects of habitat (HA), depth (IN), and sampling
date (DA) on invertebrate community structure and density of
individual taxa and from PERMANOVA pairwise tests for differences
between habitats for the periods when Cables B and A were surveyed.
Species selected were those that comprised at least 1% of all
invertebrates observed. Statistically significant effects and
differences are underlined.

Cable B                            HA       IN        DA

Invertebrate community           0.0017   0.2021    0.0238
Taxon:
Pisaster spp.                    0.0011   0.2884    0.0123
Patina miniata                   0.1528   0.9272    0.6332
Aplvsia californica              0.0327   0.4780    0.1149
Kelletia kelletii                0.1097   0.1175    0.1485
Parastichopus spp.               0.3903   0.3395    0.3746
Metacarcinus spp./Cancer spp.    0.0303   0.4645    0.7884

Cable B                          HAxIN     HAxDA     INxDA

Invertebrate community           0.0365   0.4545    0.1237
Taxon:
Pisaster spp.                    0.2881   0.0532    0.3558
Patina miniata                   0.0046   0.2595    0.1744
Aplvsia californica              0.5209   0.2109    0.0716
Kelletia kelletii                0.6568   0.6353    0.0738
Parastichopus spp.               0.4344   0.5065    0.4964
Metacarcinus spp./Cancer spp.    0.0338   0.8292    0.3765

Cable B                          Cable,   Cable,     Pipe,
                                  pipe    natural   natural

Invertebrate community           0.0354   0.0610    0.0061
Taxon:
Pisaster spp.                    0.0196   0.1248    0.0038
Patina miniata
Aplvsia californica              0.6433   0.0455    0.0020
Kelletia kelletii
Parastichopus spp.
Metacarcinus spp./Cancer spp.    0.0650   0.0423    0.8462

Cable A                            HA       IN       DA

Invertebrate community           0.0001   0.0054   0.0001
Taxon:
Pisaster spp.                    0.0001   0.0031   0.0015
Patiria miniata                  0.0001   0.1323   0.0071
Astropecten armatus              0.0190   0.0205   0.0042
Aplvsia californica              0.0007   0.2111   0.0141
Kelletia kelletii                0.2817   0.6565   0.2405
Parastichopus spp.               0.0001   0.0017   0.0246
Metacarcinus spp./Cancer spp.    0.8382   0.3927   0.4557

Cable A                          HAxIN    HAxDA    INxDA

Invertebrate community           0.0044   0.2620   0.2436
Taxon:
Pisaster spp.                    0.0091   0.5799   0.1771
Patiria miniata                  0.0008   0.1950   0.0064
Astropecten armatus              0.0573   0.1447   0.4878
Aplvsia californica              0.7424   0.0036   0.8056
Kelletia kelletii                0.7408   0.7233   0.0881
Parastichopus spp.               0.0060   0.0233   0.5548
Metacarcinus spp./Cancer spp.    0.8323   0.9260   0.9788

Cable A                          Cable,     Cable,       Pipe,
                                  pipe      natural     natural

Invertebrate community           0.0005     0.0001      0.0002
Taxon:
Pisaster spp.                    0.0009     0.1841      0.0003
Patiria miniata                  0.0003     0.0002      0.3001
Astropecten armatus              0.3525     0.0098      0.0855
Aplvsia californica              0.0174     0.0969      0.0009
Kelletia kelletii
Parastichopus spp.               0.0004   not defined   0.0002
Metacarcinus spp./Cancer spp.

Table 7. Total counts across all habitats and mean (SE)
number of invertebrates in each habitat during period when
Cable B was surveyed. Two transects, shallow and deep, were
surveyed in each habitat on 22 June-15 May 2013 sampling dates.
Number of transect surveys in each habitat, n=30.

Scientific name                    Total   CABLE B   CABLE B
                                   count    Mean       SE

Patiria miniata                     78      0.43      0.14
Pisaster spp.                       70      0.73      0.31
Aplysia californica                 19      0.33      0.12
Kelletia kelletii                   27      0.37      0.19
Parastichopus sp.                    1      0.00      0.00
Metacarcinus sp. and Cancer sp.     18      0.47      0.18
Loligo opalescens eggs              20      0.00      0.00
Pugettia spp.                       18      0.30      0.13
Loxorhvnchus spp.                   12      0.10      0.06
Dendraster excentricus              19      0.10      0.07
Octopus spp.                         2      0.03      0.03
Metacarcinus gracilis                5      0.07      0.07
Dermasterias imhricata               3      0.10      0.10
Megathura cremdata                   1      0.00      0.00
Pycnopodia helianthoides             1      0.03      0.03

Scientific name                    Pipe     Pipe     Natural   Natural
                                   Mean      SE       Mean       SE

Patiria miniata                    0.97     0.29      1.20      0.32
Pisaster spp.                      1.27     0.25      0.33      0.14
Aplysia californica                0.27     0.11      0.03      0.03
Kelletia kelletii                  0.03     0.03      0.50      0.22
Parastichopus sp.                  0.03     0.03      0.00      0.00
Metacarcinus sp. and Cancer sp.    0.07     0.05      0.07      0.07
Loligo opalescens eggs             0.67     0.67      0.00      0.00
Pugettia spp.                      0.27     0.14      0.03      0.03
Loxorhvnchus spp.                  0.13     0.06      0.17      0.08
Dendraster excentricus             0.03     0.03      0.50      0.28
Octopus spp.                       0.00     0.00      0.03      0.03
Metacarcinus gracilis              0.07     0.07      0.03      0.03
Dermasterias imhricata             0.00     0.00      0.00      0.00
Megathura cremdata                 0.03     0.03      0.00      0.00
Pycnopodia helianthoides           0.00     0.00      0.00      0.00

Table 8. Total counts across all habitats and mean (SE)
number of invertebrates in each habitat during period when
Cable A was surveyed. Two transects, shallow and deep, were
surveyed in each habitat on 14 June 2013-26 February 2014
sampling dates. Number of transect surveys in each
habitat, n=28.

Scientific name                   Total   CABLE A   CABLE A
                                  count    Mean       SE

Patiria miniata                    155     0.75      0.26
Pisaster spp.                      92      0.46      0.17
Strongylocentrotus purpuratus      100     0.00      0.00
Aplvsia californica                44      0.29      0.12
Astropecten armatus                51      0.29      0.10
Kelletia kelletii                  21      0.04      0.04
Parastichopus sp.                  21      0.04      0.04
Metacarcinus sp. and Cancer sp.     4      0.07      0.05
Pugettia spp.                       1      0.00      0.00
Loxorhvnchus spp.                   7      0.04      0.04
Octopus spp.                       10      0.07      0.07
Dermasterias imhricata              1      0.00      0.00
Pamdirus interruptus                1      0.04      0.04

Scientific name                   Pipe     Pipe     Natural   Natural
                                  Mean      SE       Mean       SE

Patiria miniata                   2.14     0.38      2.64      0.41
Pisaster spp.                     2.61     0.66      0.21      0.08
Strongylocentrotus purpuratus     3.57     3.57      0.00      0.00
Aplvsia californica               1.25     0.44      0.04      0.04
Astropecten armatus               0.43     0.12      1.11      0.37
Kelletia kelletii                 0.46     0.33      0.25      0.15
Parastichopus sp.                 0.68     0.18      0.04      0.04
Metacarcinus sp. and Cancer sp.   0.04     0.04      0.04      0.04
Pugettia spp.                     0.00     0.00      0.04      0.04
Loxorhvnchus spp.                 0.11     0.06      0.11      0.08
Octopus spp.                      0.29     0.10      0.00      0.00
Dermasterias imhricata            0.00     0.00      0.04      0.04
Pamdirus interruptus              0.00     0.00      0.00      0.00

Table 9. P-values from the repeated measures PERMANOVA testing
the effects of habitat (HA), depth (IN), and sampling date (DA)
on macrophyte community structure and density of individual taxa
and from PERMANOVA pairwise tests for differences between habitats
for the periods when Cables B and A were surveyed. Statistically
significant effects and differences are underlined.

Cable B                       HA       IN        DA

Macrophyte community        0.0001   0.0001    0.0001
Taxon:
Zostera marina              0.0001   0.2553    0.0659
Pterygophora californica    0.0001   0.0001    0.0676
Cvstoseira spp.             0.0001   0.0026    0.0019
Laminaria spp.              0.0001   0.0001    0.1713

Cable B                     HAxIN     HAxDA     INxDA

Macrophyte community        0.0001   0.0003    0.0002
Taxon:
Zostera marina              0.3820   0.1259    0.3389
Pterygophora californica    0.0001   0.1672    0.5020
Cvstoseira spp.             0.0001   0.0001    0.1156
Laminaria spp.              0.0001   0.0574    0.0395

Cable B                     Cable,   Cable,     Pipe,
                             pipe    natural   natural

Macrophyte community        0.0001   0.0001    0.0001
Taxon:
Zostera marina              0.0001   0.0001    0.0001
Pterygophora californica    0.0001   0.0001    0.0001
Cvstoseira spp.             0.0001   0.0001    0.0001
Laminaria spp.              0.0037   0.0001    0.0001

Cable A                       HA       IN        DA

Macrophyte community        0.0001   0.0001    0.0477
Taxon:
Zostera marina              0.0001   0.0001    0.0215
Pterygophora californica    0.0001   0.0001    0.6193
Cvstoseira spp.             0.0001   0.2970    0.0762
Laminaria spp.              0.0001   0.0001    0.8647
Macrocystis pvrifera        0.0001   0.0001    0.0654

Cable A                     HAxIN     HAxDA     INxDA

Macrophyte community        0.0001   0.0054    0.2401
Taxon:
Zostera marina              0.0001   0.0720    0.4107
Pterygophora californica    0.0001   0.5937    0.1637
Cvstoseira spp.             0.0001   0.6016    0.2163
Laminaria spp.              0.0001   0.9155    0.2615
Macrocystis pvrifera        0.0001   0.5037    0.0599

Cable A                     Cable,   Cable,     Pipe,
                             pipe    natural   natural

Macrophyte community        0.0001   0.0001    0.0001
Taxon:
Zostera marina              0.0001   0.0001    0.0001
Pterygophora californica    0.0001   0.0001    0.0001
Cvstoseira spp.             0.0001   0.0001    0.0001
Laminaria spp.              0.2039   0.0001    0.0001
Macrocystis pvrifera        0.0001   0.0001    0.0001

Table 10. Total count across all habitats and mean (SE)
number of macrophytes per transect in each habitat during
period when cable B and cable A were surveyed, 1 February
2012-15 May 2013 and 14 June 2013-26 February 2014, respectively.
Two transects, shallow and deep, were surveyed in each habitat on
each date. Number of transect surveys in each habitat when Cable B
and Cable A were surveyed, n=46 and n=28, respectively.

Cable B                     Total     Cable     Cable
                            Count     Mean        SE

Zostera marina              19453     16.96       3.41
Pteiygophora californica    16490    344.98       36.11
Cystoseira spp.              5223     15.65       2.50
Macrocystis pyrifera          329      3.54       1.37
Laminaria spp.               2123     18.26       3.05

Cable B                      Pipe     Pipe     Natural    Natural
                             Mean      SE        Mean        SE

Zostera marina               0.00      0.00     405.93      28.21
Pteiygophora californica    13.50      2.55       0.00       0.00
Cystoseira spp.             97.89      6.02       0.00       0.00
Macrocystis pyrifera         3.61      1.37       0.00       0.00
Laminaria spp.              27.89      4.34       0.00       0.00

Cable A                     Total     Cable     Cable
                            Count     Mean        SE

Zostera marina              22791     14.36       2.97
Pteiygophora californica      886     20.29        1.11
Cystoseira spp.              2943     17.11       1.97
Macrocystis pyrifera         5228    163.07      33.66
Laminaria spp.                892     12.39       2.61

Cable A                      Pipe     Pipe     Natural    Natural
                             Mean      SE        Mean        SE

Zostera marina               0.07      0.07     799.54      50.88
Pteiygophora californica    11.36      2.33       0.00       0.00
Cystoseira spp.             88.00      8.43       0.00       0.00
Macrocystis pyrifera        23.64      5.14       0.00       0.00
Laminaria spp.              19.46      3.80       0.00       0.00
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Author:Love, Milton S.; Nishimoto, Mary M.; Clark, Scott; McCrea, Merit; Bull, Ann Scarborough
Publication:Bulletin (Southern California Academy of Sciences)
Article Type:Report
Geographic Code:1U9CA
Date:Aug 1, 2017
Words:10660
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