Status of the Pacific sardine (Sardinops sagax) resource and fishery

California Fish and Game Code states that the annual sardine quota can be set at a level greater than 1,000 tons, providing that the level of take allows for continued increase in the spawning population. The primary goal of management as directed by the Code is rehabilitation of the resource, with an added objective of maximizing the sustained harvest. We estimate the sardine population size to have been 353,000 short tons on July 1, 1995. Our estimate was based on output from an integrated stock assessment model called CANSAR (Deriso 1993). CANSAR is a forward-casting age-structured analysis using fishery-dependent and fishery-independent data to obtain annual estimates of sardine abundance, year-class strength and age specific fishing mortality for 1983 through the first semester of 1995. CANSAR couples a simulation model with sardine population dynamics. Non-linear least-squares criteria are used to tune the model to match catch-at-age data and other indices of sardine abundance. To calculate the 1996 fishery quota, we used the harvest formula selected as the preferred option in the draft Coastal Pelagic Species-Fishery Management Plan (CPS-FMP). That formula has undergone extensive scientific and user-group review as part of the Pacific Fishery Management Council's (PFMC) CPS-FMP adoption process and has the endorsement of the fishing industry and the scientific community. Use of this formula will result in a reduced fishing mortality rate compared to the formula used to calculate the quota in 1995. We conclude that it is particularly important to reduce fishing mortality for 1996 because the rates may have been excessive in recent years, especially for older aged sardines. Accordingly, we recommend a 1996 sardine harvest quota of 35,000 short tons. (21pp.

Status of the Pacific mackerel resource and fishery 1994 and 1995

The California fishery for Pacific mackerel, Scomber japonicus, has declined precipitously since 1990, and statewide landings during 1994 totaled only 11,070 short tons. The principal cause of the low catches has been low biomass and poor availability on the traditional fishing grounds in southern California waters. Several sources of information are available on the status of the Pacific mackerel stock. Landing statistics were available since 1978 for both the U.S. and Mexican fisheries, and both fisheries show similar declines during recent years. Other fishery-independent data from aerial observations and plankton surveys (mackerel larvae samples) also show declines in abundance compared to the early 1980's. We used a tuned virtual population analysis (VPA) model called ADEPT to estimate Pacific mackerel abundance. The model finds the best statistical fit between fishery-based age-structured biomass estimates and other data from the aerial observations and the plankton surveys. A model-derived biomass estimate for July 1, 1994 was 71,000 tons. Based on the estimated number of fish in each year class at the end of 1994, and using certain assumptions concerning expected fishing mortality during the first half of 1995, we project that the Pacific mackerel biomass will be 56,000 tons at the beginning of the 1995/96 fishing season, on July 1, 1995. The Fish and Game Code specifies that when the biomass is between 20,000 and 150,000 tons, the season's quota shall be 30 percent of the biomass in excess of 20,000 tons. Using that formula and our projection for July 1, 1995, the commercial fishery quota for the 1995/96 fishing season is 10,800 tons. (21pp.

Stock assessment and management recommendations for Pacific sardine (Sardinops sagax) in 1997

The primary goal of sardine management as directed by the California Fish and Game Code is rehabilitation of the resource with an added objective of maximizing sustained harvest. Accordingly, the Code states that the annual sardine quota can be set at an amount greater than 1,000 tons, providing that the level of take allows for continued increase in the spawning population. We estimated the sardine population size to have been 464,000 short tons on July 1, 1997. Our estimate was based on output from a modified version of the integrated stock assessment model called CANSAR (Deriso et al. 1996). CANSAR is a forward-casting, age-structured analysis using fishery-dependent and fishery-independent data to obtain annual estimates of sardine abundance, year-class strength and age-specific fishing mortality for 1983 through the first semester of 1997. Non-linear least-squares criteria are used to find the best fit between model estimates and input data. Questions about stock structure and range extent remain major sources of uncertainty in assessing current sardine population biomass. Recent survey results and anecdotal evidence suggest increased sardine abundance in the Pacific Northwest and areas offshore from central and southern California. It is difficult to determine if those fish were part of the stock available to the California fishery. In an attempt to address this problem, the original CANSAR model was reconfigured into a Two-Area Migration Model (CANSAR-TAM) which accounted for sardine lost to the areas of the fishery and abundance surveys due to population expansion and net emigration. While the model includes guesses and major assumptions about net emigration and recruitment, it provides an estimate which is likely closer to biological reality than past assessments. The original CANSAR model was also used and estimates are provided for comparison. Based on the 1997 estimate of total biomass and the harvest formula used last year, we recommend a 1998 sardine harvest quota of 48,000 tons for the California fishery. The 1998 quota is a decrease of 11% from the final 1997 sardine harvest quota for California of 54,000 tons. (55pp.

An evaluation of pinniped-fishery interactions in California. A report to the Pacific States Marine Fisheries Commission (PSMFC)

(PDF has 47 pages.

Brain imaging of the cortex in ADHD: a coordinated analysis of large-scale clinical and population-based samples

Objective: Neuroimaging studies show structural alterations of various brain regions in children and adults with attention deficit hyperactivity disorder (ADHD), although nonreplications are frequent. The authors sought to identify cortical characteristics related to ADHD using large-scale studies. Methods: Cortical thickness and surface area (based on the Desikan–Killiany atlas) were compared between case subjects with ADHD (N=2,246) and control subjects (N=1,934) for children, adolescents, and adults separately in ENIGMA-ADHD, a consortium of 36 centers. To assess familial effects on cortical measures, case subjects, unaffected siblings, and control subjects in the NeuroIMAGE study (N=506) were compared. Associations of the attention scale from the Child Behavior Checklist with cortical measures were determined in a pediatric population sample (Generation-R, N=2,707). Results: In the ENIGMA-ADHD sample, lower surface area values were found in children with ADHD, mainly in frontal, cingulate, and temporal regions; the largest significant effect was for total surface area (Cohen’s d=−0.21). Fusiform gyrus and temporal pole cortical thickness was also lower in children with ADHD. Neither surface area nor thickness differences were found in the adolescent or adult groups. Familial effects were seen for surface area in several regions. In an overlapping set of regions, surface area, but not thickness, was associated with attention problems in the Generation-R sample. Conclusions: Subtle differences in cortical surface area are widespread in children but not adolescents and adults with ADHD, confirming involvement of the frontal cortex and highlighting regions deserving further attention. Notably, the alterations behave like endophenotypes in families and are linked to ADHD symptoms in the population, extending evidence that ADHD behaves as a continuous trait in the population. Future longitudinal studies should clarify individual lifespan trajectories that lead to nonsignificant findings in adolescent and adult groups despite the presence of an ADHD diagnosis

Preliminary Observations of the Effectiveness of Non-Lethal Deterrence Methods for California Sea Lions and Pacific Harbor Seals along the Coast of California

Since the Marine Mammal Protection Act (MMPA) of 1972 became a law, many pinniped populations have increased and expanded their range along the west coast of the United States (e.g., California sea lion, Pacific harbor seal, northern elephant seal, northern fur seal, Steller sea lion, etc.). Pinnipeds live primarily in the ocean but rely on coastal areas for important components of their existence (i.e., pupping and resting). As pinniped populations increase along the California coast, numbers of animals hauling out on beaches, rocky substrates, and non-traditional areas such as marinas, docks, and bait receivers have also increased. Confrontations between humans and pinnipeds are escalating. The National Marine Fisheries Service is assigned by the Federal Government to actively manage these species and their interactions with humans. These confrontations have been, in part, a result of competition between people and pinnipeds for prime coastal areas/habitat. The human responses to these interactions have included modification of marine areas used by these animals, but have also included harassment that can lead to injury or death of the animals. Pinnipeds, however, are fully protected from harm under the MMPA. The MMPA Amendments of 1994 provided new authority to citizens of the United States to deter marine mammals from damaging private property, endangering public safety, or damaging public property. A number of non-lethal deterrence methods exist, including physical barriers such as fences and negative stimuli such as sprinkler systems, rubber shot, and acoustics. In most cases, seals and sea lions become habituated to deterrence methods over time. We discuss preliminary results of the use of non-lethal techniques along the coast of California to exclude seals and sea lions from hauling out on marinas, docks, and bait receivers. Preliminary observations indicate that the placement of physical barriers and sprinkler systems has resulted in consistent non-lethal deterrence of sea lions from bait receivers and docks