Overall score: 89/100

Title: [[3/4 – you can’t really assign causality, so it should be more about associations or relationships]]

The influence of depth and habitat characteristics on a California kelp forest fish community

Zach Randell

Clarity [[ 13/14 – you’ve really worked hard on your writing skills and it shows. This is very nicely articulated and clear]]Introduction [[18/20 – nice job! You only forgot to adequately address the novelty of your study]]

An important goal of ecology is to try to understand mechanisms maintaining species diversity. Similar species are observed to thrive in rich communities without inter-specific competition driving competitive exclusion. Many models have been proposed and appropriate application differs between communities and the life history traits of those that inhabit them. The intermediate disturbance hypothesis states that species diversity will be maximized where physical or biological perturbations are neither too frequent nor too rare (Paine 1996). Forest fire for example removes low diversity old growth terrestrial forest regions allowing succession and subsequent growth of previously inhibited species (Connel 1978). Note this terrestrial example borrows components of the storage effect hypothesis because early successional species must maintain an adult population or seed bank until favorable conditions allow growth. The vast complexities of ecological dynamics limit any one model from universal application. Proposing a model requires one to carefully observe species richness, abundance and distribution across the habitat of the specific community in question. To investigate highly diverse ecosystems, the niche diversification hypothesis may aid in explaining the persistence of similar species [[the transition from intermediate disturbance to niche diversification hypotheses is a bit strange here]].

The niche diversification hypothesis limits inter-specific competition through the partitioning of a limited resource. Similar species competing over a limited resource may eventually drive one to become locally extinct. To explain the great diversity of similar species coexisting in rich communities, niche diversification proposes that natural selection drives a partitioning of resource use and thus a division of the species realized niche. For example, inshore rockfish occupying the same spatial zone within a kelp forest display specialized feeding structures that allow a variety of prey to be consumed when the temporal variability of resource input limits food (Hallacher and Roberts 1985). This allows multiple similar rockfish species to coexist without competing over a single prey item, and thus the diversity of near shore rockfish species is maintained [this is a nice clear explanation]]. Controversy surrounds this hypothesis due to documentation of unspecialized organisms thriving in rich communities. Seed dispersal and successful growth was found to be higher for unspecialized plant species [where?] (Cancella 2002). For other organisms, such as herbivores specialized for feeding on

specific plants, niche diversification appears plausible (Daugherty 2009). Specialization releases similar species from inter-specific competition and thus species diversity in enhanced. While ecological complexities limit the universal application of one specific mechanism, the niche diversification hypothesis may be suited to explain the persistence of similar species in certain rich communities.

To better understand how specialized and non-specialized species partition resources we must investigate a highly diverse ecosystem. Kelp forests are one of the most diverse ecosystems in the world. This system supports an impressive array of fish, algae and invertebrate species. The three dimensional biogenic habitat created by giant kelp (Macrocystis pyrifera) provides settlement for larvae completing the first stage of their bipartite life cycle who then in turn attract a host of predators. Massive growth paired with seasonal turnover provides a plethora of organic material for grazer and scavenger consumption (Duggins 1989). One such kelp forest is located at Hopkins marine station in Monterey California. An ideal study site, the marine community at Hopkins has been protected from human interference since 1931. Studying this unspoiled ecosystem is aided by benthic installations that allow for standardization and repeatability of a sampling protocol. [nice!]

To understand the mechanisms maintaining diversity in this rich ecosystem, our study aims to answer three questions. 1) Does the relative abundance of fish species vary as a function of depth zone? 2) Does the composition of fish species differ as a function of depth zone? 3) Are the physical and biological habitat characteristics different between depth zones? If so, we seek to determine whether depth acts alone or in conjunction with variable habitat to produce any observed differences in the fish community structure. An answer to each question alone is insufficient to understand differences of fish species, yet together, the answers will allow us to propose mechanisms ftor how physical and biological habitat is partitioned by type and depth to support the vast diversity of fish species observed in a kelp forest. [[good explanation of questions]]

Methods [[16/18]]

Study site Observational subtidal surveys recorded habitat, algae and fish species in a giant kelp

forest (Macrocystis pyrifera) community at Hopkins Marine Station (Fig. 1). Protected from human intervention since 1931, Hopkins allows for the study of an unspoiled marine community. Residing just inside the southern region of Monterey Bay, (36° 37’ 17.02” N, 121° 54’ 07.28” W) The Hopkins kelp forest resides on a descending depth gradient with variable habitat composition and structure. [[why the word resides? It’s a strange word for to use for a kelp forest]]

Fig. 1. Kelp forest at Hopkins marine station

Fig. 1. A permanent incrementally labeled cable installed along the bottom provided repeatable anchorage, allowing multiple days of observation across the variable benthic habitat. Repetition of multiple survey types over quantified habitat allowed us to determine whether the Hopkins fish community composition is dependent upon variable depth and the associated physical and biological habitat.

The kelp forest at Hopkins is ideally suited forto investigatinge the effect of differing benthic habitat upon species composition and abundance due to the high diversity of species found across variable depth and benthic structure (Bodkin 1988 Braken et al. 2004). Granitic rock interrupted by sporadic sand patches provides habitat for a diverse assemblage of fish, invertebrates and algae. Physical relief of the benthic

substrate varies from flat to high, providing an abundance of structure type available for biological use. Seasonal upwelling provides abundant nutrient delivery and thus habitat for recruitment drives interspecific competition in benthic species (Watanabe 1984).

The methods used to answer our three questions are explained below, followed by an analysis of species accumulation that allowed us to assess how appropriate the scope of our sampling protocol was. Next we break down the three surveys used: UPC, algae swath and fish swath concluding with general protocol methods.

Fish species abundance as a function of zoneThe relative abundance of fish species are predicted to differ as a function of zone. To

determine if the relative abundance varied by zone, we performed observational benthic fish surveys. Scouring the bottom for relatively conspicuous benthic fish and taking snap shot midwater fish observations provided all data for analysis [sounds like you used a camera, you should be a little more clear]. To assess fish species differences between depth regions we sampled on either side of the permanent cable. Offshore, (“deep zone” 90°) followed the depth contour down eleven meters, while onshore, (“shallow zone” 270°) sloped upwards to nine meters. The sampling of different depth zones allowed us to depict the density of species per transect by zone, enabling us to answer whether relative fish abundance differed as a function of zone. The data was analyzed with a chi square analysis. Using a null hypothesis that species abundance was not dependent upon zone, the raw observations were tested against a predictor variable (zone) to determine the extent of independence and ultimately whether species abundance is a function of zone.

Fish species composition as a function of zoneThe composition of the fish community is predicted to differ between the deep and

shallow zone. The same observational subtidal benthic fish data collected to address abundance was used to determine whether fish species composition differed between the deep

and shallow regions at Hopkins. The data was compiled into a graph that represents the percent composition of species seen in the deep and shallow regions. Each depth zone totals to 100%, allowing the relative contribution of each species compared to the others within and against [across?] depth zones.

Fish species accumulation analysisTo test the reliability of observed species composition and abundance we performed a

resampling analysis to produce a fish species accumulation graph. Each 30 meter transect was broken into six sequential five meter segments. These segments, In addition to comparing the fish community with segments of previously classified habitat, allowed for the resampling of species within segments to produce a rough estimate of the number of species likely to be found after sampling a given number of segments. This allows us to compare the expected number of species between deep and shallow regions, permitting us to not only answer whether fish species accumulation differs by zone, but where exactly species richness and evenness is maximized. As this analysis offers insight into community organization, we can assess how reliable our survey protocol was with comparisons to known Central California kelp forest communities. [[should probably talk about the slope and the assymptote of those graphs and what they mean]]

Physical and Biological Habitat as a function of zoneThe physical and biological habitat is predicted to differ between the two depth zones.

The predicted differences are also expected to offer insight into specific habitat associations driving any observed difference in fish species. To test this question we incorporate physical habitat data along with counts of conspicuous algae together will fish survey data collected along the same cable marking and transect headings. The 30 meter transects were broken into increments of five meters [10 sq m would be more accurate], allowing species comparisons with small spatial scale of habitat. Two surveys explained below provided the required physical and biological habitat characterization.

[[Data Collection methods? You need a subheading here to indicate that you’re switching into a more detailed description of sampling methods]]Uniform point contact, (UPC)

Observational subtidal UPC surveys characterized benthic habitat by recording substrate, physical relief and primary substrate holder. Substrate was grouped into sand, cobble (<10cm), boulder (10cm-1m) and bedrock (>1m). Relief was broken into flat (0-10cm), low (10cm – 1m), medium (1m-2m) and high (>2m). Primary substrate holder was grouped into encrusting, sessile invertebrate and algal species unpractical or impossible to be individually counted. Every half meter along a thirty meter transect tape was sampled, resulting in a 30 x 1 meter surface of quantified habitat for a single transect. The UPC method allowed a percent coverage to be calculated for each category of substrate holder observed. This provided the baseline percent coverage of respective substrate, relief and primary substrate holder that allowed comparison with all subsequent biological observational surveys.

Algae swath surveys

Divers performed observational subtidal algae surveys off of the permanent transect cable at Hopkins. Macrocystis pyrifera, and to a lesser extent Cystoseira osmundacea, are known to facilitate recruitment. Both species were counted to determine abundance across the variable benthic habitat. Survey data allowed us to look for associations between the two algae species and specific habitat characteristics. This allowed us to determine any potential effect they may have on the distribution and composition of the fish community at Hopkins. Mirroring the protocol from the previous habitat study allowed a precise comparison between UPC, swath and fish data.

Fish surveysWe sought to observe 24 species of solitary and schooling fish (Table 1). Species were

observed over 40 transects, 20 in each depth zone. Individuals were recorded in the specific segment along the transect tape in which they were observed: (0-5m), (5-10m), (10-15m), (15-20m), (20-25m) or (25-30m). Observation by segments allowed comparisons to be drawn with previously quantified habitat with the ultimate goal of discovering fish species-habitat association patterns, and how these patterns are affected by depth.

Protocol [[I think this is redundant with the above? I would recommend it with the more detailed descriptions of different survey methods and paring it down]]

10 pairs of divers located a pre-assigned meter marker along the permanent cable (90 m – 135m, 5m increments, 10 tie-off points total) indicating the appropriate place to initiate sampling. Divers used a 30 meter transect tape to sample offshore (“deep”, 90°) and inshore (“shallow, 270°) of their respective meter mark.

For UPC, divers completed one transect per dive, sampling once offshore and once inshore (two dives total). Along one 30 meter transect we sampled twelve 2.5 meter stretches with 5 points within each 2.5 meter increment. A total of 240 points were gathered for a single transect with 4,800 points gathered for all 20 transects. 600 square meters of benthic habitat was quantified for relief, substrate and primary substrate holder.

For invert and algae swath surveys, two dives, one transect per dive, one onshore and one offshore provided all data for analysis. We split each transect into six sequential five meter segments (20 transects, 120 segments, each segment 10 square meters). This permitted a smaller scale of resolution for data analysis as we compared swath species in one segment to the habitat previously classified in that exact segment. 1200 square meters of benthic substrate was observed.

For fish surveys, divers completed two benthic transects per dive, sampling the bottom and two meters around and above the transect tape. First, one transect was completed offshore (90°), and then a reciprocal (270°) onshore transect staggered 5 meters off of the initial survey (two deep transects) returned the dive team to the cable. For the second dive we sampled onshore of the cable (270°) then performed a reciprocal offshore transect back to the cable. Two dives, two deep transects and two shallow transects per dive team at each of the 10 locations along the cable. 40 transects, each sampling 30x2x2 meters, totaled 4800 square meters of seawater observed for fish.

Results [[13/16]]

Differences in the fish species abundance and composition found at two different depths at Hopkins were discovered. The accumulation analysis returned implications for the physical and biological habitat results, both of which differed between depth zones. Below we offer results of each question and present the accumulation analysis. [[you should actually say what you found (broadly) at the beginning of the results section]]

Fish species abundance as a function of zoneThe results supported our prediction that fish species abundance would differ as a

function of zone (Fig. 2). Our data showed that there is a difference in the relative abundance at the two zones. We found a greater relative abundance of fish in the deep in comparison with the shallow (X2 = 60.04, df=18, p=0.000001). Notably, schooling perch and rockfish species were found in greater numbers in the deep zone compared to the shallow zone. The deep zone at our Hopkins study site had a positive effect on the abundance of fish species observed.

Fig. 2. Mean number of individuals observed Fig. 3. Species percentage as a as a function of zone function of zone

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Fig. 2. Fish abundance was in greater in Fig. 3. With both zones totaling to 100%, the the deep zone compared to the shallow. species composition comprising each region 19 species of fish were seen more often than can be observed. Note demersal fish comprisethe 14 species observed in the shallows. Note the largest percentage represent in the the five most abundance species observed in shallow, compared to the schoolingin the deep are all schooling fish save for fish found in the deep.Sebastes atrovirens.

Fish species composition as a function of zoneOur prediction that there would be a difference in the composition of fish species as a

function of zone was supported post data analysis. The deep zone was comprised of 19 fish species while the shallow zone contained 14 species. (Fig. 3). In the shallow zone, a smaller number of species encompassed a larger percentage of observations when compared to the

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relatively similar contribution of species in the deep zone. Thus the deep zone was comprised of more species than the shallow zone.

Fish species accumulation analysisA larger number of species were encountered with greater frequency and regularity in

the deep (Fig. 4.) as represented by the red line below. Note how the initial rate is larger which indicates that the abundance, the frequency of a species encountered, was consistently greater in the deep zone. Comparing accumulation data with the abundance and composition data suggested that our survey scope was not sufficient to account for all species habitat associations.

Fig. 4. Species accumulation dependent upon number of segments

Fig. 4. The number of accumulated species observed is dependent upon number of segments sampled, and differs by depth as represented by the red and blue lines. Based on the resampling of species number within a random collection of any given size of segments.

Physical and biological habitat varying by zoneThe data supported our prediction that physical and biological habitat would vary as a

function of zone. The percent coverage of both substrate and relief varied between the deep and shallow regions (Fig. 5 and Fig. 6). Specifically, more sand was found in the deep compared to the bedrock found in the shallows. Our data indicated that the permanent cable runs along an apparent but not exclusive sand-reef interface.

Building upon our physical habitat, the percentage of Macrocystis pyrifera and Cystoseira osmundacea comprising biological habitat also differed as a function of zone (Fig. 7). A greater percentage of M. pyrifera and C. osmundacea were found in the shallows compared to the deeps. Our results indicate that physical and biological habitat varied between deep and shallow regions. The effect of variable habitat upon the differences in fish community structure will be addressed below. Fig. 5. Percent of substrate as a function of zone Fig. 6. Percent of relief as a function of zone

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Fig. 5. UPC surveys found the sand in the deep Fig. 6. Flat relief was found at a greater and bedrock in the shallow were found to be percentage in the deeps (associated with the greatest differences in substrate composition. sand) while the shallows had a higherResults suggest different yet comparable percentage of low relief (associated withbenthic composition at Hopkins. bedrock). .

Fig. 7. Macro algae percentage as a function of zone

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Fig. 7. Cystoseira osmundacea and Macrocystis pyrifera were both found to cover a larger percentage of the shallow region. This depth partitioning was more apparent in C. osmundacea opposed to Macrocystis pyrifera.

Discussion [[20/22 – some very interesting explanations you propose here and quite nicely structured if a bit long]]

The deep and shallow fish community at Hopkins differed in abundance and composition. Physical habitat also varied by depth and we will attempt to tease apart the relative importance between changing depth and varying habitat influencing the Hopkins fish community. Below we discuss how variable biological and physical habitat acted in conjunction across two depth regions to produce differences in fish species composition and abundance. We conclude with an accumulation analysis to provide insight into the effectiveness of our sampling protocol to allow improvement for future kelp forest fish studies.

Fish species abundanceOn a basic level, fish abundance was greater in the deep zone. Note that schooling fish

were found in both depth zones, yet were vastly more abundant in the deeps (Fig. 2): Black perch (Embiotoca jacksoni), pile perch (Rhacochilus vacca), and the blue rockfish (Sebastes mystinus). Differences in habitat substrate and relief may offer insight into mechanisms maintaining the observed abundance differences. The deep zone was comprised of a larger percentage of sand, while the shallows were found to be made up of more bedrock (Fig. 5). Supporting these findings were the differences in relief (Fig. 6), which was flatter in the deeps (associated with sand), and low in the shallow (associated with bedrock). We thus conclude that a sand-reef interface exists along the transect cable, and the deep region can be considered to be part of a tapering edge of the kelp forest at Hopkins.

Previous work found that the schooling blacksmith (Chromis punctipinnis) massed on the edge of Southern California kelp forests, intercepting plankton as incurrent and outcurrent motions flushed water in and out of the kelp forest (Bray 1981). Drag from the kelp canopy

reduces the flow of water thus plankton density is likely highest on the outer edge of the kelp forest. This hypothesis may explain the large abundance of the planktivore S. mystinus found in the deep. Opposed toInstead of [[opposed to sounds like the fish have a moral opposition to eating plankton]] consuming plankton, R. vacca has been shown to prey upon small invertebrates that emerge at night from the sand (Hueckel and Stayton 1982). Foraging preference may explain the large perch abundance above the sandy regions of the deep zone. The high fish abundance of schooling species on the observed sand-reef interface likely allows protection from pelagic predators while foraging on their preferred prey. [[this is one of the best proposed explanations for your results that I’ve read yet!]]

The gopher rockfish (Sebastes carnatus) was found exclusively in the deep zone, while the black and yellow rockfish (Sebastes chrysomelas) was found to comprise a larger percentage of the shallow zone. Experimental manipulation revealed S. chrysomelas outcompetes S. carnatus for shallow benthic habitat (Larson 1980). Removal plots demonstrated S. chrysomelas did not move to deeper depths when S. carnatus was removed, yet S. carnatus moved to shallow depths upon removal of S. chrysomelas. Inter-specific competition results in a habitat partitioning that in turn drives a difference in prey type consumption. (Hallacher 1985). Both rockfish have very similar maxillary, gill and intestine length, yet in poor upwelling seasons consume different prey. Ironically, the gopher rock fish, outcompeted to deeper regions, is the only rockfish Hallacher sampled that did not have an increased likelihood of an empty stomach during poor upwelling seasons. Our evidence supports competition driving a partitioning of habitat use and thus the coexistence of two very similar species through different prey preference. However, it should be noted that the observed depth partitioning was not absolute. S. chrysomelas was still seen in the deep, just not as often as it was seen in the shallow. S. carnatus was only seen twice in the deep zone and not at all in the shallow zone. This suggests that the deep zone surveyed was not “deep enough” to observe all likely species habitat utilization differences within the kelp forest at Hopkins. It could be argued that the 9-11 meters surveyed only encompass a shallow region, with a small amount of species mixing from deeper regions. Further studies into depth partitioning would benefit from sampling deeper regions that are logistically feasible on SCUBA, perhaps around 20m.

Fish species compositionFor differences in fish species composition, note the density of prominent species found

in both the deep and shallow zones (Fig. 3). Black perch (Embiotoca jacksoni), pile perch (Rhacochilus vacca), and the blue rockfish (Sebastes mystinus) were found in both zones but at over twice the density in the deeps of that of the shallows. All these species are mobile and known to school. In contrast, we have mostly demersal species found at a greater percentage in the shallow zone: striped perch (Embiotoca lateralis), painted greenling (Oxylebius pictus), the black and yellow rockfish (Sebastes chrysomelas) and the black eye goby (Rhinogobiops nicholsii). One conclusion is that the larger percentage variable rocky reef (Fig. 5 and Fig. 6) provides ample shelter for a greater number of demersal fish. While perfectly logical, we must dig a little deeper to understand why the rocky reef provides habitat in the shallow region.

Understanding differences in the biomechanical method of propulsion between the two groups of fish may shed light on the observed composition differences. Swimming can be

characterized by the specific fins predominantly used to exert thrust (Lindsey 1978), and different motions employed effect the swimming efficiency and tolerance of fish against high water movement (Webb 2004). The shallow demersal fish may rely on pectoral motions for lift, while the deeper schooling fish use caudal motions to provide propulsion. It could be argued that the demersal fish species method of swimming allows a greater tolerance against physical disturbance. Similar results were found to explain differences in the fish composition in response to physical water disturbances on a coral reef (Fulton 2005). Different methods of propulsion may represent specializations allowing high water movement-tolerant fish species to exploit food and habitat resources unfavorable to mobile schooling fish. One then must question whether food availability in the shallows drove adaptation to tolerate high water motion, or if competition drove demersal species out of the water column and fueled the subsequent adaptation and specialization to benthic life. In either case, the observed depth partitioning is evidence for niche diversification maintaining an increased diversity by encouraging adaptation to habitats susceptible to increased physical disturbance. [[interesting explanation and not one I’ve seen in anyone else’s paper]]

However, there is an exception to the mechanical mode of propulsion determining shallow composition hypothesis – the striped perch (Embiotoca lateralis) was observed a greater percentage of the time in the shallows (Fig. 3). This species likely relies on the caudal motion of swimming we predominantly observed in the deep. E. lateralis has been shown to be competitively dominant over the black perch, Embiotoca jacksoni (Hixon 1980). Experimental removal manipulations showed E. jacksoni readily moved to shallow habitat once clear of E. lateralis, while E. lateralis had no interest in deeper habitat cleared of E. jacksoni. Our data supports these findings, and on a basic level represents a partitioning of habitat by zone. Opposed to refuting our mechanical mode of swimming hypothesis, E. lateralis tolerance to harsh water movement may represent an adaption allowing the exploitation of resources less frequented by their fellow caudal swimming species. Observing the composition of E. lateralis across varying levels of water movement intensity could shed light on the behavior explaining the high shallow composition [[high shallow composition doesn’t mean anything]].

Fish species accumulationAnalyzing fish accumulation allows us to assess the overall differences in the fish

community at Hopkins, while secondly permitting hindsight into the reliability of our survey protocol. Fish accumulation was found to be greater in the deep zone compared to the shallow zone (Fig. 4). The blue line representing the shallow zone begins to asymptote upon the resampling of 35 segments. We would expect to encounter all 14 shallow fish species after surveying 35 segments (5.8 transects, or after covering 175 x 2 x 2 meters cubed of sea water). Additional sampling would not yield an increase in the number of fish species encountered. In contrast, after 35 segments are resampled in the deep, not all 19 species are likely to have been encountered, and additional sampling would be required if full community classification is desired.

Five fish species found in the deeps were absent from the shallows. The kelp perch, Brachyistius frenatus, was one of them. This is a peculiar result as B. frenatus has been documented to be positively influenced by Macrocystis pyrifera (Anderson 1994). Juveniles were shown to be associated with the canopy while the adults were distributed along kelp

stipes of varying depth. According to our algae surveys M. pyrifera covered a greater percentage of the shallows, (56% vs 44% in the deep, Fig. 7) yet the only sightings of B. frenatus were in the deep zone (Fig. 2). The increased percentage M. pyrifera in the shallows is supported by the greater habitat complexities of high relief bedrock (Fig. 5 and Fig. 6). Not only did the kelp perch not appear in the expected depth zone, but it did not appear in the depth zone containing a greater abundance of the algae known to have a positive effect on kelp perch abundance. The lack of sightings in the shallows suggests that the scope of our sampling would have benefited from the inclusion of surveying the kelp canopy to account for all potential biological habitat associations.

Cymatogaster aggregata data presented another zone composition anomaly. The shiner perch becomes reproductively active in the spring and summer months where it schools in near shore shallow waters (Darling et al 1980). Only one sighting in the deep zone was made of the shiner perch (Fig. 2). This suggests that not only did we not sample the correct biological habitat, but our shallow surveys were simply not shallow enough to account for all likely species. As our sampled shallow zone bottomed out at 9 meters, future studies seeking to improve sightings of these expected yet absent species would benefit from midwater SCUBA surveys. Drawing conclusions about differences in biological and depth zone utilization are difficult without sampling all the spatial regions known to be occupied by the target species.

Despite our survey protocol under-sampling all potential biological habitat, in regards to the fish assemblage at Hopkins, we can state the deep zone is more diverse than the shallow zone. As diversity is a measure of species richness and evenness, the deep zone had a larger number of species consistently encountered compared to the shallow zone, whose species were similar but smaller in number and less frequently encountered. As a basic interpretation of the data, schooling fish regularly encountered in groups of multiple individuals likely resulted in the increased accumulation line seen in the deeps. To contrast against the shallows, deimersal fish seen alone probably contributed to the lower initial rate and subsequently smaller accumulation of species observed.

Several differences between the deep and shallow zones may either act together or independently to encourage a greater number and frequency of fish species to be observed in the deep zone. It is difficult to tease apart the relative importance of both depth and habitat acting upon fish communities. To further understand the extent of species accumulation dependent upon the physical disturbances associated with shallower waters, we could sample benthic, mid-water and the canopy simultaneously across a variety of surge and wind wave conditions. This protocol sampled over a variety of substrate would provide data for the respective importance of habitat and depth. If the accumulation lines were found to be close together for both deep and shallow species during calm conditions, we would suggest that differences in depth alone do not affect abundance and composition, but that the increase in physical disturbance associated with shallow waters chases off certain species. If a similar difference in the accumulation lines displayed by fig. 4 were found during calm conditions, we would then turn, as we argued above, to conclude that habitat differences in the deep and shallow zones influence fish habitat associations and subsequent foraging specializations.

Table 1: All fish species searched for at Hopkins

Blue rockfish Sebastes mystinus

Striped perch Embiotoca lateralis

Black rockfish Sebastes melanops

Black perch Embiotoca lateralis

Kelp rockfish Sebastes atrovirens

Rubberlip perch Rhacochilus toxotes

Gopher rockfish Sebastes carnatus

Pile perch Damalichthys vacca

Black/Yelow rockfish Sebastes chrysomelas

Kelp perch Brachyistius frenatus

Copper rockfish Sebastes caurinus

Shiner perch Cymatogaster aggregata

Canary rockfish Sebastes pinniger

Rainbow perch Hypsurus caryi

Olive rockfish Sebastes serranoides

Blackeyed goby (>8cm) Rhinogobiops nicholsii

Lingcod Ophiodon elongates

Cabezon Scorpaenichthys

marmoratusKelp greenling Hexagrammos

decagrammusSenorita

Oxyjulis californica

Painted greenling Oxylebius pictus KGB

OYT

Table 1: This comprises all fish species we sought to observe. (Juvinillies represented are difficult to exactly identify – KGB and OYT. They are incorrectly but for ease of reading referred to as a species due to their habitat utilization that differs from adult conspecifics.) 19 were species were encountered in the deeps, 14 of those 19 were encountered in the shallows.

Referances [[6/6]]

Anderson, T. 1994. Role of macroalgal structure in the distribution and abundance of a temperate reef fish. Marine Ecology, Volume 114, pp. 278-290. Bodkin, J. L. 1988. Effects of kelp forest removal on associated fish assemblages in central California. J.Exp.Mar.Biol.Ecol. 117:227-238.

Bray, R. 1981. Influence of water currents and zooplankton densities on daily foraging movements of blacksmith, Chromis punctipinni, a planktivorous reef fish. Fishery Bulletin, Vol. 78.

Cancela, M. C. 2002. Spatial patterns of seed dispersal and seedling recruitment in Corema album (Empetraceae): the importance of unspecialized dispersers for regeneration. Ecology. 90: 775-784

Connell, J. H. 1978. Diversity in tropical rain forests and coral reefs. Science 199: 1302-1310

Darling, J. Noble, M. Shaw, E. 1980. Reproductive strategies in the surfperches. I. Multiple Insemination in Natural Population of the Shiner Perch, Cymatogaster aggregata. Evolution, Vol. 34, pg 271-277.

Daugherty, M. P. 2009. Specialized feeding modes promote coexistence of competing herbivores: Insights from a metabolic pool model. Environmental Entomology, 38:667-676.

Duggins, D. O. Simenstad, C. A. Estes, J. A. 1989. Magnification of secondary production by kelp detritus in coastal marine ecosystems

Fulton, C. Bellwood, D. 2005. Wave-induced water motion and the functional implications for coral reef fish assemblages. Limnology and Oceanography. Vol 50, pp 255-264.

Hixon, M. 1980. Competitive interactions between California reef fishes of the Genus Embiotoca. Ecology Vol. 61, pp. 918-931.

Huekel, G. Stayton, L. 1982. Fish foraging on an artificial reef in Puget Sound, Washington.Marine Fisheries Review, Vol. 44, pg 6-7.

Lindsay. 1978. Form, function and locomotory habitats in fish. Fish physiology, pp. 100-110

Paine, R.T. 1996 Food Web Complexity and Species Diveristy. American Naturalist 100: 65-75

Juanes, F. 2007. Role of habitat in mediating mortality during the post-settlement transition phase of temperate marine fishes. Journal of Fish Biology. Vol 70, pg 661-677.

Watanabe, J. M. 1984. The influence of recruitment, competition, and benthic predation on spatial distribution of three sprecies of kelp forest gastropods (Trochidae: Tegula). Ecology 65: 920-936

Webb, P. 1994. The biology of fish swimming mechanics. Physiology of animal swimming, pp. 45-62