Kelp Bass Paralabrax Clathratus Research Articles

Physiological and Behavioral Effects of Angling Stress on Kelp Bass, an Important Game Fish in Southern California

AbstractGame fish populations in North America face increasing pressure from recreational anglers, yet sublethal effects from mandatory catch‐and‐release regulations remain unknown for many targeted species. In southern California, Kelp Bass Paralabrax clathratus populations have significantly declined in recent decades, prompting changes in management and increasing release rates. To assess acute effects of current fishing regulations, we collaborated with recreational anglers to evaluate short‐term, sublethal impacts of capture stress on Kelp Bass physiology and behavior. To evaluate the timeline and magnitude of physiological stress, blood samples were collected at time points (10–120 min) after angling and confinement and compared to control fish sampled in less than 3 min. Postrelease recovery was determined by comparing biomarker levels between control fish and recaptured fish that were rapidly sampled after a time at liberty ranging from 3 h to 186 d. Biomarker levels in fish recaptured multiple times were compared to previous samples to evaluate repetitive angling effects on physiological responses. Circulating cortisol, glucose, and lactate were elevated and steadily increased in the hour after capture, although angling duration and handling duration were not correlated with biomarker response. Fish size significantly affected fish stress, with larger fish experiencing less stress and rapid recovery within 24 h. Behavioral control fish, which ingested acoustic accelerometers hidden inside bait, exhibited strong diel activity that was reduced for 30 h in angled fish. Tracked individuals exhibited high individual variation in rate of movement and area use, with no noticeable postrelease impacts. Although this study found Kelp Bass to be resilient to angling stresses, evaluation of long‐term effects from catch and release is warranted. This fishery may also benefit from slot limit regulations, improved angler engagement programs, and education on best practices that minimize fish stress during catch and release.

Secondary Production of Kelp Bass Paralabrax clathratus in Relation to Coastal Eelgrass Zostera marina Habitat in a Southern California Marine Protected Area

Seagrasses are an important refuge for fishes and provide ecosystem services worldwide. Along the Pacific Coast, however, quantitative assessments of the ecological role of seagrass habitats with limited anthropogenic impacts are lacking despite their value to resource management. To address these issues, the ecological function of the eelgrass Zostera marina Linnaeus in a protected area off Santa Catalina Island, California, USA was quantified using estimates of secondary production in the kelp bass Paralabrax clathratus (Girard, 1854). Monthly assessments of Zostera structural complexity, as well as the size and abundance of juvenile kelp bass were used to establish a baseline of fish biomass and recruitment associated with Zostera habitat. The greatest number of kelp bass was recorded in the summer and fall months and the fewest during the winter and spring. Secondary production in kelp bass (0.1 to 0.59 g m–2 mo–1) followed monthly changes in Zostera habitat structure throughout the 24-month study period. Seasonal changes in the structural complexity of coastal Zostera beds may influence the flow of energy to adjacent reef environments through the transfer of fish biomass. These findings help define the potential role of Zostera habitat within the larger context of nearshore coastal ecosystems in the Southern California Bight.

Limited recruitment of an ecologically and economically important fish, Paralabrax clathratus, to an invasive alga

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 602:213-224 (2018) - DOI: https://doi.org/10.3354/meps12673 Limited recruitment of an ecologically and economically important fish, Paralabrax clathratus, to an invasive alga Samuel C. Ginther*, Mark A. Steele California State University Northridge, Department of Biology, Northridge, CA 91330-8303, USA *Corresponding author: samuel.ginther@csun.edu ABSTRACT: Some invasive species have devastating ecological impacts on native species, whereas others have little effect. The macroalga Sargassum horneri recently invaded the waters of California (USA) and Mexico, and in some places has largely replaced an important native macroalga, the giant kelp Macrocystis pyrifera. To explore the potential impacts of the invasive alga on populations of an ecologically and economically important fish, the kelp bass Paralabrax clathratus, we tested whether recruitment of kelp bass onto macroalgae differed between the invasive S. horneri and native M. pyrifera. Field surveys by scuba divers on naturally occurring S. horneri and M. pyrifera at Santa Catalina Island revealed that kelp bass recruits were ~30 times more abundant on individual M. pyrifera than on individual S. horneri. To assess the cause of this pattern, we conducted a field experiment in which plots containing 3 treatments (M. pyrifera only, S. horneri only, and M. pyrifera and S. horneri together) were isolated over a sandy bottom, which limited post-settlement movement of recently settled kelp bass among macroalgae. Kelp bass recruitment was similar for the 2 treatments containing M. pyrifera, but no recruits were observed on S. horneri, regardless of whether the alga was alone or paired with M. pyrifera. Additionally, we found a strong spatial gradient in recruitment among the experimental plots that was explained by the abundance of larger, cannibalistic conspecifics. This study presents the first evidence that invasive S. horneri may negatively impact an important reef fish. KEY WORDS: Sargassum horneri · Macrocystis pyrifera · Kelp bass · Santa Catalina Island Full text in pdf format PreviousNextCite this article as: Ginther SC, Steele MA (2018) Limited recruitment of an ecologically and economically important fish, Paralabrax clathratus, to an invasive alga. Mar Ecol Prog Ser 602:213-224. https://doi.org/10.3354/meps12673 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 602. Online publication date: August 23, 2018 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2018 Inter-Research.

Taking the chaos out of genetic patchiness: seascape genetics reveals ecological and oceanographic drivers of genetic patterns in three temperate reef species

Marine species frequently show weak and/or complex genetic structuring that is commonly dismissed as 'chaotic' genetic patchiness and ecologically uninformative. Here, using three datasets that individually feature weak chaotic patchiness, we demonstrate that combining inferences across species and incorporating environmental data can greatly improve the predictive value of marine population genetics studies on small spatial scales. Significant correlations in genetic patterns of microsatellite markers among three species, kelp bass Paralabrax clathratus, Kellet's whelk Kelletia kelletii and California spiny lobster Panulirus interruptus, in the Southern California Bight suggest that slight differences in diversity and pairwise differentiation across sampling sites are not simply noise or chaotic patchiness, but are ecologically meaningful. To test whether interspecies correlations potentially result from shared environmental drivers of genetic patterns, we assembled data on kelp bed size, sea surface temperature and estimates of site-to-site migration probability derived from a high resolution multi-year ocean circulation model. These data served as predictor variables in linear models of genetic diversity and linear mixed models of genetic differentiation that were assessed with information-theoretic model selection. Kelp was the most informative predictor of genetics for all three species, but ocean circulation also played a minor role for kelp bass. The shared patterns suggest a single spatial marine management strategy may effectively protect genetic diversity of multiple species. This study demonstrates the power of environmental and ecological data to shed light on weak genetic patterns and highlights the need for future focus on a mechanistic understanding of the links between oceanography, ecology and genetic structure.

Realized and potential larval connectivity in the Southern California Bight

Populations of many nearshore marine species are connected through the dispersal of their larvae. In this paper, larval connectivity patterns in the Southern California Bight are explored using 2 quantities: potential and realized larval connectivity. Potential connectivity is defined as the probability of larval transport from a source to a destination location and is quantified using Lagrangian particle simulations. Realized connectivity is the product of potential connectivity with larval production and can be used to estimate larval settlement patterns. Potential and realized con- nectivity patterns are quantified for kelp bass Paralabrax clathratus, kelp rockfish Sebastes atro- virens, and red abalone Haliotis rufescens, 3 species with a range of larval dispersal characteristics. Connectivity patterns were found to be both heterogeneous, with locations having different source and destination strengths, and asymmetric, with directionality in larval transport. Both potential and realized connectivity were strongly influenced by the length and timing of the spawning season as well as planktonic larval duration. For kelp bass and kelp rockfish, a strong correspondence was found between realized and potential destination locations, suggesting that circulation processes have a dominant role in shaping the spatial distribution of these 2 species. Strong temporal variabil- ity in realized larval connectivity was observed on seasonal and inter-annual time scales (particularly between El Nino and La Nina conditions). These results provide novel information for use in marine fisheries and conservation management.

Development and inheritance of molecular markers in the kelp bass Paralabrax clathratus

Keywords Mendelian Microsatellite Mitochondrial Paralabrax SerranidaeWhile molecular tools have transformed fisheries biology,their development and implementation can necessitate theuse of delicate equipment, be expensive, and requireextensive optimization [1]. Counting only consumables, wehave calculated that in-house sequencing of 500–700 baseson a Beckman CEQ 8000 (Beckman Coulter, Fullerton,CA, USA) costs *$4–5 per sample under ideal conditions.It is a process not amenable to isolated or rudimentary labconditions and is not easily performed as a quick-returnassay. Loci scored as dye-labeled fragments on an auto-mated sequencer are also expensive [2]; they requiredevelopment of a microsatellite library and cost commer-cially *US$12,500 [3]. Confirmation of Mendelianinheritance in the marker set is yet another cost burden andrepresents an important but infrequently performed pre-requisite for statistical testing. A recent survey found 1 in15 microsatellite loci, as expressed in their data scores, hadnon-Mendelian patterns [4].The reporting of methodologies and inheritance studiesthat are cost effective and have minimal equipmentrequirements can therefore be invaluable to a new researchprogram or a monitoring effort that requires fast turn-around times. A set of markers will be available for thespecies in question and frequently its congeners; thestrategies for developing the markers, such as our inheri-tance methodology below, can have even widerapplication. Based on this rationale, this short paper pre-sents genetic methods developed for the kelp bass,Paralabrax clathratus, that confirm the robustness ofmarkers and allow for economical and expeditious assays.Kelp bass are a temperate serranid found abundantly fromPoint Conception, CA, to just south of Punta Eugenia,Mexico [5], and are an important component of the$300 million California sport fishing industry [6, 7]. P.clathratus occurs in current and proposed southern Cali-fornia marine reserves and has been the subject of adiversity of research [8–11].We document a restriction fragment length polymor-phism (RFLP) assay of the mitochondrial control regionthat can assess a substantial amount of the sequencediversity with only a thermal cycler and an agarose gel box.We also present a series of controlled crosses to confirmMendelian inheritance for previously published microsat-ellite markers [12], a task generally difficult to performwith many marine fish [13].Development of RFLPsSequences for the mitochondrial control region of 105 kelpbass from ten locations (Genbank accession numbersDQ192295–DQ192399) were used. Sequences werealigned in Sequencher 4.5 (Gene Codes, Ann Arbor, MI,USA) and surveyed with the program’s restriction enzymelibrary. Pairwise U

Reproductive behaviour of a temperate serranid fish,Paralabrax clathratus(Girard), from Santa Catalina Island, California, U.S.A.

The reproductive behaviour of the kelp bassParalabrax clathratuswas studied on Santa Catalina Island, California, U.S.A. from April 2000 to September 2002. Adults formed aggregations of three to > 200 individuals, and spawning occurred within subgroups of three to 23 individuals that contained a single female. The gonado‐somatic index (IG) of collected ripe males (mean = 5·8%, range = 0·5–13·1%) indicated a large investment in sperm production that is common in group‐spawning fishes characterized by intense sperm competition. Spawning occurred 32 min before sunset to 120 min after sunset, and both males and females were capable of spawning multiple times during a single evening. Behavioural observations of adults and estimates of spawning periodicity from the collection of females with hydrated oocytes suggested that spawning occurred continuously throughout the summer months and showed no significant relationship with the lunar cycle. In general, the spawning behaviour of kelp bass was similar to other functionally gonochoric, group‐spawning serranids. The dynamics ofP. clathratusspawning aggregations, however, were inconsistent with that of tropical reef fish spawning aggregations, including the transient spawning aggregations of some tropical serranids. Aggregation spawning appeared to be an important component of the annual reproduction of this species.

Analysis of mtDNA haplotypes of kelp bass tests for sibling-dominated recruitment near marine protected areas of the California Channel Islands

Marine protected areas (MPAs) have been heralded as the next important fisheries management tool. Predicted benefits include increased fish biomass, increased species diversity, and enhanced recruitment to the MPA itself, as well as to proximal areas. Whereas MPAs have in fact been shown to increase biomass and species diversity, evidence of enhanced recruitment has yet to be seen. If MPAs are significantly enhancing recruitment, one would expect to see the recruitment dominated by groups of siblings arising from highly productive females predicted to eventually reside in MPAs due to the protection afforded them. If occurring, such sibling-dominated recruitment could be identified by significantly fewer mtDNA haplotypes and significantly fewer singleton hap- lotypes in population samples of recruiting juveniles compared to adult populations. We investigated a new approach for potentially determining whether MPAs might be significantly enhancing recruit- ment to proximal areas of Santa Cruz and the Santa Catalina islands in the California Channel Islands, by seeking evidence of sibling-dominated juvenile recruitment in mitochondrial DNA haplo- type data of the kelp bass Paralabrax clathratus. Our analyses found largely genetically mixed recruitment from the plankton, suggesting that recruitment to the sampled areas was not being mea- surably enhanced from point sources such as the nearby MPAs.

Movement patterns, home range, and habitat utilization of adult kelp bass Paralabrax clathratus in a temperate no-take marine reserve

Home range, activity patterns, site fidelity and habitat preference of the kelp bass Para- labrax clathratus were determined from 12 adult fish tracked using acoustic telemetry within a tem- perate no-take marine reserve (0.13 km 2 ). Home range sizes ranged from 33 to 11 224 m 2 , averaging 3349 ± 3328 m 2 (±SD), but did not correlate with fish size. Fish were active and occupied similar-sized activity spaces during both day and night. Kelp bass exhibited a high degree of site fidelity, remain- ing resident in core areas for up to 3 yr. Relative to the total amount of available habitat, kelp bass showed a habitat selection preference for rock boulder, rock rubble and kelp habitat. These habitats offer high vertical relief, shade and large holes for shelter, and may attract and facilitate prey capture. Average home range size was 3% of the area of the reserve. Only 1 of 12 tracked fish crossed the reserve boundary, but this accounted for less than 5% of the fish's time. Natural habitat breaks along the reserve boundary may have further limited adult kelp bass movements. The small home ranges and high site fidelity of kelp bass in this reserve indicate that the reserve is effective in protecting the resident adult stock.

A simple method for estimating larval supply in reef fishes and a preliminary test of population limitation by larval delivery in the kelp bass Paralabrax clathratus

This paper describes a method for estimating larval supply of a temperate reef fish, the kelp bass Paralabrax clathratus, that is simple, inexpensive, requires relatively low effort, and inte- grates larval supply over time. Using this method, we sampled larval supply concurrently at 4 sites spread over about 35 km for nearly an entire settlement season. With these data and visual estimates of recruitment (the density of young-of-the-year after the end of the settlement season), we tested the hypothesis that spatial patterns in recruitment were set by larval supply. This hypothesis was rejected: kelp bass recruitment to the 4 sites was not related to patterns of larval supply. Furthermore, in contrast to the findings of an earlier study, recruitment was not related to the density of the macroalga Macrocystis pyrifera. Recruitment was, however, strongly correlated with the density of 1 yr old kelp bass, suggesting that spatial patterns of recruitment were consistent between the 2 cohorts. Recruitment, however, was not correlated with the density of bass 2+ yr old. We also mea- sured larval supply in a second year and found that spatial patterns of supply were strongly corre- lated between years at a relatively small scale of 10s to 100s m, but not at a larger scale of several km. This finding suggests that some deterministic process (or set of processes) sets spatial patterns of larval supply at small, but not large scales. At large scales, consistent patterns of recruitment between 2 cohorts in the face of variable larval supply suggest that deterministic, postsettlement pro- cesses may generate predictable patterns of recruitment even when the supply of larvae is variable. In addition to demonstrating that spatial patterns in the abundance of demersal fish are not always well predicted by larval supply, this study introduces a technique that may facilitate more thorough exploration of the role of larval supply in determining the dynamics of populations of reef fishes.

Site fidelity and homing behaviour of some kelp‐bed fishes

Common species of kelp‐bed fishes including adult blacksmith Chromis punctipinnis, adult senorita Oxyjulis californica, and sub‐adult kelp bass Paralabrax clathratus were collected from two separate and isolated rocky reefs at Santa Catalina Island, California, U.S.A. where giant kelp Macrocystis pyrifera was present. After tagging, groups of fishes were either returned to their initial collection site or displaced to an alternative kelp‐bed site to measure site fidelity and homing behaviour. No tagged fishes that were returned to their initial collection sites and subsequently resighted, exhibited any movement to another reef suggesting that these fishes have a limited home range, and handling during capture and tagging had no effect on site fidelity. Of fishes translocated to alternative kelp‐bed sites, up to 80% of tagged senorita and 100% of tagged blacksmith that were resighted had returned to the site of their initial collection, indicating that these species are motivated and able to relocate previously utilized areas when displaced. However, when young‐of‐the‐year and juvenile kelp bass were displaced, none were ever seen again suggesting that disruption of the relationship between a young kelp bass and its home site may influence its survival.

Site fidelity and homing behaviour of some kelp-bed fishes

Common species of kelp-bed fishes including adult blacksmith Chromis punctipinnis, adult senorita Oxyjulis californica, and sub-adult kelp bass Paralabrax clathratus were collected from two separate and isolated rocky reefs at Santa Catalina Island, California, U.S.A. where giant kelp Macrocystis pyrifera was present. After tagging, groups of fishes were either returned to their initial collection site or displaced to an alternative kelp-bed site to measure site fidelity and homing behaviour. No tagged fishes that were returned to their initial collection sites and subsequently resighted, exhibited any movement to another reef suggesting that these fishes have a limited home range, and handling during capture and tagging had no effect on site fidelity. Of fishes translocated to alternative kelp-bed sites, up to 80% of tagged senorita and 100% of tagged blacksmith that were resighted had returned to the site of their initial collection, indicating that these species are motivated and able to relocate previously utilized areas when displaced. However, when young-of-the-year and juvenile kelp bass were displaced, none were ever seen again suggesting that disruption of the relationship between a young kelp bass and its home site may influence its survival.

Ammonium excretion by macroinvertebrates and fishes on a subtidal rocky reef in southern California

Macrofauna living on subtidal rocks reefs in southern California excrete ammonium, a potentially important nutrient for benthic algae. Ammonium excretion rates of eleven macroinvertebrate and five fish taxa were determined from a total of 324 in situ incubations conducted between October 1984 and August 1985 at 14 to 17 m depths off Santa Catalina Island, California. Total ammonium excretion ranged from over 100 μmol h-1 by the kelp bass Paralabrax clathratus to less than 0.1 μmol h-1 by the gastropod Conus californicus. Weight-specific ammonium excretion generally ranged from 0.5 to 4 μmol g-1 h-1 in invertebrates and from 3 to 7 μmol g-1 h-1 in fishes. Intraspecific excretion rates varied substantially. Coefficient of variation of excretion rates were higher than reported for laboratory studies and multiple regression indicated that 50 to 90% of the variation in ammonium excretion rates of five species studied in detail could not be explained by the combined variation in dry weight, water temperature, time of day, and incubation dates. The excretion data, along with estimates of population densities and size-frequency distributions, indicate that benthic macrofauna release a total of 25 to 30 μmol NH 4 + m-2 h-1 both day and night. The species that generally make the largest contributions are a gobiid fish (Lythrypnus dalli), followed by three gastropods (Astraea undosa, Tegula eiseni, and T. aureotincta) and a sea urchin (Centrostephanus coronatus). The amount of ammonium excreted by these macrofauna on rocky reefs is insignificant compared to our previously published data on the nighttime excretion of blacksmith (Chromis punctipinnis), a pomacentrid fish that feeds in the water column during the day and shelters on the reef at night. Including blacksmiths, we estimate that the amount released by rocky-reef macrofauna at night is >280 μmol m-2 h-1, a rate that is similar to that for many other marine communities. Additional studies are required to determine if benthic algae utilize ammonium released by these macrofauna, especially at night.

Effects of predation risk on foraging behavior: mechanisms altering patch choice

Responses of foraging young-of-year black surfperch Embiotoca jacksoni Agassiz to benthic predators, kelp bass Paralabrax clathratus (Girard) and grass rockfish Sebastes rastrelliger (Jordan and Gilbert), were investigated in laboratory and field experiments. Young-of-year black surfperch fed on crustacean prey from a variety of benthic algal substrata. In laboratory experiments using uniform patches of a favored alga, black surfperch avoided kelp bass or grass rockfish by reducing time spent feeding in a patch containing a predator, although no effect on the feeding rate of the surfperch was observed. Surfperch showed no difference in their response to kelp bass or grass rockfish. Field experiments indicated that, under conditions of safety, the low-growing alga Zonaria farlowii Setchell and Gardner was the most highly favored substratum. As risk of predation increased, preference for Zonaria declined sharply and the tall, bushy alga Sargassum palmeri Grun became the most highly favored feeding substratum. The mechanisms producing the shift in preference involved an increased number of visits to Sargassum and a longer duration foraging bout per visit. The responses of young-of-year black surfperch to piscivorous fishes appear to enable the surfperch to reduce mortality risk while still continuing to feed actively.