The Fish Assemblages Inside and Outside of a Temperate Marine Reserve in Southern California

The purpose of this investigation was to evaluate the effect of a small marine reserve (established 1988) on a temperate rocky reef fish assemblage at Santa Catalina Island, California. Fish surveys on SCUBA were conducted at two reserve and two non-reserve sites from October 2002 to January 2004. Sites were similar in fish density, species richness and biomass of the entire fish assemblage. However, the adult densities of two important fishery species, California sheephead (Semicossyphus pulcher; 7.6 0.5 and 5.5 0.4/100 m2 inside versus outside) and kelp bass (Paralabrax clathratus; 3.6 0.4 and 2.9 0.4 inside versus outside), were significantly higher within the reserve. The reserve appears to be effective in increasing density and biomass of two impacted species that were readily observed and surveyed on SCUBA

The Fish Assemblages Inside and Outside of a Temperate Marine Reserve in Southern California

Volume: 105Start Page: 128End Page: 14

The Reef Fish Assemblage of the Outer Los Angeles Federal Breakwater, 2002–2003

Volume: 104Start Page: 63End Page: 7

An empirical test of the ‘shark nursery area concept’ in Texas bays using a long-term fisheries-independent data set

Using a long-term fisheries-independent data set, we tested the ‘shark nursery area concept’ proposed by Heupel et al. (2007) with the suggested working assumptions that a shark nursery habitat would: (1) have an abundance of immature sharks greater than the mean abundance across all habitats where they occur; (2) be used by sharks repeatedly through time (years); and (3) see immature sharks remaining within the habitat for extended periods of time. We tested this concept using young-of-the-year (age 0) and juvenile (age 1+ yr) bull sharks Carcharhinus leucas from gill-net surveys conducted in Texas bays from 1976 to 2006 to estimate the potential nursery function of 9 coastal bays. Of the 9 bay systems considered as potential nursery habitat, only Matagorda Bay satisfied all 3 criteria for young-of-the-year bull sharks. Both Matagorda and San Antonio Bays met the criteria for juvenile bull sharks. Through these analyses we examined the utility of this approach for characterizing nursery areas and we also describe some practical considerations, such as the influence of the temporal or spatial scales considered when applying the nursery role concept to shark populations.Publishe

Demographic Parameters of Yellowfin Croaker, Umbrina roncador (Perciformes: Sciaenidae), from the Southern California Bight.

v. ill. 23 cm.QuarterlyThe yellowfin croaker, Umbrina roncador Jordan & Gilbert, 1882, is a common nearshore and surf-zone species in the southern California bight. Age was determined for individuals (n ¼ 1,209) using annual increments in otoliths, and size at age was modeled using the von Bertalanffy growth curve (Ly ¼ 307:754 mm, k ¼ 0:278 yr_1, t0 ¼ _0:995 yr; maximum age ¼ 15 yr). Females (Ly ¼ 313:173 mm, k ¼ 0:307 yr_1, t0 ¼ _0:771 yr) grew significantly faster and larger than males (Ly ¼ 298:886, k ¼ 0:269 yr_1, t0 ¼ _1:072 yr). Age and growth modeling based upon otolith length (OL) and width (OW ) measurements were assessed and were consistent with body measurements. Males and females were found in all size classes and in an overall 51 :49 ratio that was not significantly different from a 50% sex ratio, suggesting that these fish are gonochores. Fish were reproductive during summer months, with gonadosomatic indices (females, 5.65%; males, 5.51%) consistent with group-spawning fishes. Data from two separate monitoring programs indicated that yellowfin croaker catch-per-unit-effort (CPUE) fluctuated appreciably from 1992 to 2006 on both spatial and temporal scales. CPUE also declined significantly in the latter years of these programs. Based on samples collected between 2003 and 2004, an estimate of overall annual total mortality was A ¼ 0:4492, and instantaneous coefficient of total mortality was estimated at Z ¼ 0:5964. Recruitment year classes were back calculated using annual survivorship. Year class strength was variable and declined significantly by the end of this study. Considering the high temporal and spatial variation in estimates of abundance and recruitment, coupled with the likelihood that these fish employ a probable group-spawning reproductive behavior, we recommend a cautious approach for the future management of this species