A time series of 22 samples collected in April and July were taken of the fish assemblages of San Diego Bay over 11 non-consecutive years from 1995 to 2019. Each sample consisted of four ecoregions using a variety of collection methods designed to assess all components of the ichthyofauna. These samples yielded a total of 525,288 fishes belonging to 90 species and weighing 3,507 kg over the 25-year period. Northern anchovy was the most abundant fish species comprising 41% of the total catch despite its virtual absence near the end of the survey period, followed by topsmelt, slough anchovy, shiner perch, and Pacific sardine. Round stingrays dominated in weight constituting more than 27% of the total biomass taken followed by spotted sand bass, and northern anchovy. Approximately 64% of all individual fish captured in San Diego Bay during this study were juveniles. In a canonical correlation analysis, temperature, distance from the mouth of the bay, and salinity accounted for nearly 93% of the variance in individual species abundances. In the time series analyses, we found all three potential temporal patterns of fish species abundance, biomass, and diversity, namely: 1) significant decreases over time, 2) significant increases over time, and 3) no significant change over time. Abundance of eight of the top 35 species (including northern anchovy, topsmelt, slough anchovy, and shiner perch) and all forage species combined decreased over the study. Two species increased significantly in abundance, spotted sand bass and dwarf perch. Whereas, total abundance, total biomass, species richness, Shannon diversity, and the majority (71%) of species abundances did not change over the 25-year period. Despite various environmental perturbations and the general trends of decreases in larval and fish abundance indices over the Southern California Bight in recent years, the stability in species richness and composition over time reflects the generally resilient nature of the fish assemblage structure of San Diego Bay that has been maintained by active management including restoration practices.

In many marine ecosystems worldwide, overfishing is a prominent cause in removing large predatory fishes from ecological communities. Fluctuation in the abundance of higher trophic level species can transform an ecosystem's structure and function by altering trophic interactions through density-mediated top-down control. Accordingly, understanding the extent to which humans indirectly influence a community through altering predator abundance is of critical importance. Thus, during the summer of 2013 and 2014 the impacts of fishing on the trophic structure of kelp forest fishes were examined within the Southern California Bight. In 2013, we tested whether decreased abundance through fishing for higher trophic level predators relieves predation pressure on lower trophic level prey. Using a combination of underwater survey techniques, density (no. fish/100 m2) and biomass (g/100 m2) of conspicuous fish species were sampled inside and outside of three long-standing Marine Protected Areas (MPAs) off La Jolla, Santa Catalina Island, and Anacapa Island, California. We found that the secondary carnivore and herbivore/omnivore trophic levels were significantly lower in density and biomass outside of MPAs. Inversely, the primary carnivore trophic level biomass was higher outside of MPAs. At the species level, we observed a lower abundance outside MPAs of large kelp bass (>25 cm) and higher densities of potential prey, kelp perch. Other primary carnivore fishes (blacksmith and señorita) showed a non-significant trend of higher biomass outside MPAs. Our results provide evidence of trophic level changes due to fishing pressure and provide support for a possible weakening of top-down control on specifically the kelp perch population through the removal of large kelp bass outside MPAs. The removal or recovery of predators can greatly influence an ecosystem. As more recent studies suggest that indirect community effects of fishing and protection can take up to decades to detect, it is necessary to document the continued changes on the structure, function, and dynamics of the kelp forests and rocky reefs off southern California.

Co- operation in the management of shared fish stocks is often necessary to achieve sustainability and reduce uncertainty. The United States of America (USA) and Mexico share a number of fish stocks and marine ecosystems, while there is some binational co- operation in scientific research, unilateral management decisions are generally the rule. We present a case study using the giant sea bass ( Stereolepis gigas , Polyprionidae) to highlight how these management and research asymmetries can skew national perceptions of population status for a fully transboundary species. Scientific publications and annual funding related to giant sea bass are 7x and 25x higher in the USA, respectively, despite the fact that 73% of the species’ range occurs in Mexico. Conversely, annual fishery production and consumptive value of giant sea bass in Mexico are 19x and 3.5x higher than in the USA, respectively, while the non-consumptive value related to dive ecotourism is 76x higher in the USA. These asymmetries have generated a distorted view of the population status of the giant sea bass across its entire range. This and other factors related to historical fishery dynamics and policy must be accounted for when assessing population status, and subsequent appropriate management responses, across geopolitical boundaries.

In 2015 the Pacific Ocean experienced a strong El Niño Southern Oscillation (ENSO). With this change in water temperature, marine species were able to expand outside their previous ranges and settle in new habitats. The first sighting of the species Labrisomus xanti, or largemouth blenny, on Santa Catalina Island was October 2015 and since then the species has been seen regularly around the island. In October and November of 2018, we surveyed three sites along the leeward side of Catalina Island. Largemouth blennies were counted, measured, and sex determined along diver transects at multiple depth strata. Substrate type was also recorded. We observed multiple sizes of largemouth blennies among sites, depths and between sexes. Among the three sampled locations, Empire Landing had significantly more individuals than Big Fisherman Cove and Yellowtail Point. These differences were likely due to the greater abundance of small and medium-sized boulders and lack of sand patches within the rocky reef at Empire Landing. Male largemouth blennies were significantly larger than females. The largest largemouth blennies were found at a depth of 4.5 m with the smallest individuals found in the shallow (1.5 m) depths. Individuals were significantly larger at Empire Landing and Yellowtail Point than at Big Fisherman Cove. Finally, length frequency analysis identified at least four putative age classes corresponding to the years 2014–2017 supporting a well-established population. However, further study is necessary before we can determine whether the population at Catalina Island is a self-sustaining population.

The giant sea bass (GSB), Stereolepis gigas Ayres, 1859, is the largest teleost (exceeding 2 m in length and 200 kg in weight) and megacarnivore found in California kelp forest communities. Overfishing of GSB in the late 1920s crashed the population off California and in 1996 it was classified as an International Union for Conservation of Nature (IUCN) critically endangered species. Recently, three GSB were collected off San Onofre, California and held at the Southern California Marine Institute in San Pedro. Two of the three GSB were infected with Lepeophtheirus longipes Wilson, 1905 (Siphonostomatoida; Caligidae), a poorly described species of parasitic copepod previously recorded from the GSB and purportedly on other fish hosts. In this study, a detailed redescription of the female and the first description of the male of L. longipes are provided and all records of Lepeophtheirus longipes are reviewed. The latter revealed that L. longipes is host specific to GSB. Lepeophtheirus longipes is distinguished from its congeners by a combination of female characters that includes: (1) genital complex with prominent posterolateral lobes and is about half the length of the cephalothorax and just over two times longer than the cylindrical, indistinctly 2-segmented abdomen; (2) an antennule with a small conical process on the proximal segment; (3) maxillule with an outer conical process at the base of the dentiform process; (4) sternal furca with pointed and slightly splayed tines; (5) first exopodal segment of leg 3 with a terminal spine; and (6) third exopodal segment of leg 4 with three unequal apical spines.

Several studies have been conducted on the California coast investigating the distribution and abundance patterns of rocky intertidal fishes; however, most of these studies have focused on only one or two sites along a large expanse of coastline primarily north of Point Conception. This study examined six sites in the central portion of the Southern California Bight to assess regional patterns of abundance and distribution of rocky intertidal fishes more accurately. All six sites were sampled within the same low tide series quarterly from January 2004 to February 2005. Species abundances, biomass, densities, species diversity (H′), and size distributions were determined and compared. All assemblages were dominated by Clinocottus analis (Cottidae) both in abundance and biomass although a total of ten species were found throughout the study representing six families. Species composition did vary with latitude as warm temperate species, Girella nigricans and Gobiesox rhessodon, were associated with southern sites, and cool temperate species, Clinocottus recalvus and Oligocottus snyderi, were found at northern sites. Differences in community structure may reflect site specific environmental conditions such as surfgrass coverage or wave energy. When considering abundance and density, each metric yielded a different result, i.e., the site with greatest abundance had the lowest density. This may be reflective of a funneling effect of intertidal fishes from surface area of habitat available at high tide to low tide rather than simply standardizing for pool size. H′ was not influenced by season or latitude but was negatively correlated with wave exposure. Three of the five most common species (Clinocottus analis, Girella nigricans and Gobiesox rhessodon) recruited in the late fall, early winter. Assessment of Clinocottus analis by site revealed regional variation: recruitment was only detected at the three southern sites in January 2004 but at all six sites in February 2005.

Conversion of biomass into fermentable sugars is a major requirement for successful and cost-effective biofuels production. The conversion of xylan to sugars requires multiple enzymes including α-glucuronidase. Here we report the cloning, expression, purification and characterization of the α-glucuronidase from Dictyoglomusturgidum(DtuAgu). DtuAgu is an intracellular protein of 685 amino acids and a predicted molecular weight of 79.4 kD. Enzymatic activity was optimum between pH 7.0 and 8.0 and at 85°C. The specific activity of the enzyme was 10 u/mg when measured using mixed aldouronic acids. The specific activity on isolated glucuronoxylan was approximately 20% of the value obtained with xylooligosaccharides. DtuAgu significantly improved xylan conversion to xylose when evaluated using two mixtures of thermostable bacterial enzymes and two sources of xylan. DtuAgu has the potential to be a key player in thermostable enzyme cocktails for the conversion to biomass to biofuels.α

For fishes that migrate to specific locations to spawn within large aggregations at predictable times, fishery independent surveys of the abundance, distribution, and population structure of adult fish at spawning aggregation sites can provide valuable data for fisheries monitoring and assessments. We tested the feasibility of using high resolution, split-beam sonar to estimate the distribution, abundance, and group sizes of Barred Sand Bass (Paralabrax nebulifer) at their primary spawning aggregation site off Huntington Beach, California, in July 2010 and July 2012. We established an in-situ target strength distribution for Barred Sand Bass using tethered fish, collected hydroacoustic data opportunistically over the entire spawning grounds, and validated acoustic data with concurrent video surveys and rod and reel sampling of fishes present within the survey area. The modal target strength of Barred Sand Bass was determined to be -35 dB and was distinct from other fish species present. Groups of Barred Sand Bass averaged 30 individuals in abundance and ranged from 2 to 1,711 individuals, with the vast majority of the groups containing less than 10 individuals. Groups of Barred Sand Bass were most abundant in the water column between 5 and 10 m below the surface over bottoms depths of 20 to 30 m, resulting in a negative relationship between group size and depth. Due to the sand bottom habitat of the spawning site, the tendency for fish to aggregate to spawn in the water column during predictable periods, and the low diversity of other fish species present at the spawning site during the peak spawning months, hydroacoustic surveys of primary spawning aggregation sites represent an efficient, practical method for regional population monitoring and fishery assessments of Barred Sand Bass.

This study provided a first detailed description of the acoustic calls and the possible sound production mechanism in the Giant Sea Bass (Stereolepis gigas). Passive acoustic (hydrophone) recordings of Giant Sea Bass sounds were made of three mature individuals (40–45 kg) held in a circular 17,000 l seawater tank isolated from other fish species. Four basic sounds plus combinations were identified from the tank recordings when fish were present and were encountered on numerous occasions throughout the study. We classified the basic sounds as two types of pulses (A and B), short bursts, and long bursts, and combinations of short and long bursts. Mean peak frequencies of the four sound types were less than 39 Hz, while mean durations ranged from 67 ms to 545 ms, depending on sound type. We also obtained and dissected two mature, adult Giant Sea Bass to describe the morphology of a putative sound production mechanism. Five putative sonic muscles were discovered between each of the first six pleural ribs of the male examined. These five massive muscles (=obliquus superioris?) unite ribs 3 to 9 and were found at the level of the deep hypaxial musculature. The identification of these sounds and accompanying sonic mechanism marks the first occurrence of sound production in the family of wreckfishes (Polyprionidae). This knowledge of the acoustic characteristics increases our ability to document the presence, activity, and possibly the abundance of this critically endangered species at spawning sites.

Trichoderma reeseiβ-glucosidase (Bgl1) is one of four enzymes demonstrated to act synergistically to degrade cellulose both in vitro and in vivo. Our work attempted to better understand the substrate specificity and potential biotechnological applications of Bgl1. T. reesei Bgl1H cleaves over 80% of the β-(1-4) and β-(1-3) linkages in β-glucan and 14% of the β-(1-4) linkages in amorphous cellulose, significantly more than any tested bacterial β-glucosidase. Bgl1H cleaves 50% of the β-(1-4) linkages in xyloglucan when supplemented with cellulase and α-xyloside. Approximately 20% conversion to glucose was obtained from insoluble β-(1,3)-linked curdlan using only Bgl1H; addition of a curdlanase resulted in conversion of approximately 70% of the curdlan to glucose. Bgl1H also produces xylose from xylooligosaccharides and debranched xylans. For both glucans and xylans, the relative rates of hydrolysis increase with increasing polysaccharide chain lengths. Bgl1H is able to partially degrade β-glucan in a variety of grain components; addition of endo-acting enzymes improved the enzyme’s performance on these grain components. The ability of this enzyme to produce monosaccharides from undigestible polysaccharides suggest it may have potential in improving utilization of carbohydrates in animal feed, fermentations, and other biotechnological applications.

We made extensive observations in the shallows off sandy beaches along the southern California coastline from 2013-2018 using SCUBA. The common diurnal behavior of young-of-the-year (YOY) of giant sea bass, Stereolepis gigas, were documented, in detail, and categorized while they occupied their unique nursery areas. We identified and described the frequently observed behaviors referred to as 1) "kelping", 2) "resting", 3) "traveling", and 4) "burying". Finally, through direct observation, mysid shrimp were confirmed as the primary diet of young-of-the-year of the giant sea bass off southern California. This is the first study to provide a behavioral overview of the YOY of this internationally listed, endangered species, and it bridges important gaps in our understanding of their early life history.

EcologyVolume 100, Issue 1 e02496 The Scientific Naturalist Baby Giants are found at the heads of submarine canyons Larry G. Allen, Corresponding Author Larry G. Allen larry.allen@csun.edu Department of Biology, California State University, Northridge, California, 91330 USAE-mail: larry.allen@csun.eduSearch for more papers by this authorStephanie A. Benseman, Stephanie A. Benseman Department of Biology, California State University, Northridge, California, 91330 USASearch for more papers by this authorMichael Couffer, Michael Couffer Grey Owl Biological Consulting, Corona del Mar, California, 92625 USASearch for more papers by this author Larry G. Allen, Corresponding Author Larry G. Allen larry.allen@csun.edu Department of Biology, California State University, Northridge, California, 91330 USAE-mail: larry.allen@csun.eduSearch for more papers by this authorStephanie A. Benseman, Stephanie A. Benseman Department of Biology, California State University, Northridge, California, 91330 USASearch for more papers by this authorMichael Couffer, Michael Couffer Grey Owl Biological Consulting, Corona del Mar, California, 92625 USASearch for more papers by this author First published: 21 August 2018 https://doi.org/10.1002/ecy.2496Citations: 1 Corresponding Editor: John Pastor. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume100, Issue1January 2019e02496 RelatedInformation

This study identified nursery habitat, recruitment patterns, the planktonic larval duration (PLD), size and age at settlement, and growth rate of the young-of-the-year (YOY) Giant Sea Bass (GSB), Stereolepis gigas, off Southern California. A total of 160 YOY GSB were sighted on 150 transects over a three-year period. Young-of-the-year GSB were relatively rare (maximum density of 40/ha) and recruitment was limited to a few areas. In 2014–2015, densities of YOY GSB were significantly higher at six locations off sandy beaches nearest the heads of submarine canyons off Redondo Beach, Newport Beach, and La Jolla, California. The vast majority of occurrences of YOY (73%) were within 500 m of the heads of submarine canyons. Three color phases of YOY were discovered ranging (smallest to largest individuals) from black to brown to orange. Recruitment occurred from July through February with peak abundances occurring in the late summer months from August through October. YOY occurred at depths from 2 m to nearly 10 m. Overall, size of YOY GSB increased with depth in the shallow sand riffle zone. YOY grew rapidly at 1.23 mm/day (n = 23) with collected individuals ranging from 31 to 84 d old based on daily ring increments in otoliths. The planktonic larval duration was estimated to be about one lunar month (26.8±2.4 d) based on the presence of the first settlement check and size of earliest settlers. Size at settlement was estimated to be 14.4±3.0 mm TL (10.6±2.5 mm standard length [SL]). This information adds substantially to our knowledge of early developmental processes and recruitment patterns of Giant Sea Bass that are crucial to our understanding of their life history and to making informed decisions regarding fisheries management policies and conservation efforts.

The goal of this work was to clone, express, characterize and assemble a set of soluble thermostablecellulases capable of significantly degrading cellulose. We successfully cloned, expressed, and purified eleven Clostridium thermocellum (Cthe) cellulases and eight Acidothermuscellulolyticus(Acel) cellulases. The performance of the nineteen enzymes was evaluated on crystalline (filter paper) and amorphous (PASC) cellulose. Hydrolysis products generated from these two substrates were converted to glucose using beta-glucosidase and the glucose formed was determined enzymatically. Ten of the eleven Cthe enzymes were highly active on amorphous cellulose. The individual enzymes all produced <10% reducing sugar equivalents from filter paper. Combinations of Cthe cellulases gave higher conversions, with the combination of CelE, CelI, CelG, and CelK converting 34% of the crystalline cellulose. All eight Acel cellulases showed endo-cellulase activity and were highly active on PASC. Only Acel_0615 produced more than 10% reducing sugar equivalents from filter paper, and a combination of six Acel cellulases produced 32% conversion. Acel_0617, a GH48 exo-cellulase, and Acel_0619, a GH12 endo-cellulase, synergistically stimulated cellulose degradation by the combination of Cthe cellulases to almost 80%. Addition of both Acel enzymes to the Cthe enzyme mix did not further stimulate hydrolysis. Cthe CelG and CelI stimulated cellulose degradation by the combination of Acel cellulases to 66%.