Sumilon Island reserve: 20 years of hopes and frustrations

Over 20 years, successive openings and closures of the Sumilon Island marine reserve to fishers have provided unique opportunities to examine the effects of marine reserves on populations and communities of fishes and upon local fisheries. The history of the reserve also highlights the problems and frustrations of educating and convincing people of the need for rational management of renewable marine resources. Yet, it is a symbol of hope in that it has provided a unique example of the potential benefits of marine reserves in fisheries management, particularly in the developing world.

Fifty years of reservoir fisheries in Mettur Dam, India: some lessons

The paper outlines briefly the history of the fishery in a dam reservoir in India. The reservoir was very productive in its early years, with support from a seed farm, ice plant, cold storage and regulated entry of fishery. However, once entry restrictions were relaxed and closed fishing seasons no longer enforced, the yield of fish from the reservoir declined.

The U.S. Gulf of Mexico Pink Shrimp, Farfantepenaeus duorarum, Fishery: 50 Years of Commercial Catch Statistics

U.S. Gulf of Mexico, pink shrimp, Farfantepenaeus duorarum, catch statistics have been collected by NOAA’s National Marine Fisheries Service, or its predecessor agency, for over 50 years. Recent events, including hurricanes and oil spills within the ecosystem of the fishery, have shown that documentation of these catch data is of primary importance. Fishing effort for this stock has fluctuated over the 50-year period analyzed, ranging from 3,376 to 31,900 days fished, with the most recent years on record, 2008 and 2009, exhibiting declines up to 90% relative to the high levels recorded in the mid 1990’s. Our quantification of F. duorarum landings and catch rates (CPUE) indicates catch have been below the long-term average of about 12 million lb for all of the last 10 years on record. In contrast to catch and effort, catch rates have increased in recent years, with record CPUE levels measured in 2008 and 2009, of 1,340 and 1,144 lb per day fished, respectively. Our regression results revealed catch was dependent upon fishing effort (F=98.48df=1, 48, p<0.001, r2=0.67), (Catch=1,623,378 + (520) × (effort)). High CPUE’s measured indicate stocks were not in decline prior to 2009, despite the decline in catch. The decrease in catch is attributed in large part to low effort levels caused by economical and not biological or habitat related conditions. Future stock assessments using these baseline data will provide further insights and management advice concerning the Gulf of Mexic

Forty Years of Winter: Cetaceans Observed During the Southbound Migration of Gray Whales, Eschrichtius robustus, Near Granite Canyon, Central California

From December to February in most years from 1967 to 2007, observers counted gray whales, Eschrichtius robustus, from shore sites south of Carmel in central California. In addition to gray whales, other cetacean species were also recorded. These observations were summarized and compared among survey platforms and to ocean conditions. Eleven cetacean species were identified including eight odontocete species (killer whale, Orcinus orca; Pacific white-sided dolphin, Lagenorhynchus obliquidens; common dolphin, Delphinus spp.; bottlenose dolphin, Tursiops truncatus, northern right whale dolphin, Lissodelphis borealis; Risso’s dolphin, Grampus griseus; Dall’s porpoise, Phocoenoides dalli; and harbor porpoise, Phocoena phocoena) and three mysticete species (humpback whale, Megaptera novaeangliae; minke whale, Balaenoptera acutorostrata; and blue whale, Balaenoptera musculus). As expected, the detection of certain species among survey platforms (shore-based census watches, 25-power “Big Eye” binocular watches, and aerial surveys) was limited by species surfacing behavior and/or bathymetric preference. Comparisons among the shore-based census efforts showed a significant difference in sightings rates from 1967–84 (n = 14, mean = 0.11, SD = 0.11) to 1985–2007 (n = 11, mean = 1.48, SD = 0.47; t-Test: p < 0.001, df = 23). The warm period observed during the 1990’s may partially explain the increase in sighting rates and diversity of species observed at the census site compared to the much cooler temperatures of the 1970’s.

An overview of 1000 years of tropical climatic variability from ice cores from the Andes of southern Peru [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Each summer between 1976 and 1984 research was conducted on the Quelccaya Ice Cap with one central objective, to recover an ice core to bedrock from which an approximate 1000 year climatic history for tropical South America could be reconstructed. In 1983 that central objective was accomplished by recovering one core 155 meters in length containing 1350 years and a second core of 163.6 meters containing more than 1500 years of climatic history. ... The most significant climatic event in tropical South America over the last 1500 years was the "Little Ice Age" which is recorded between 1490 to 1880 A.D. in these ice core records. Records from the summit of the Quelccaya Ice Cap show that during the "Little Ice Age" period there was (1) a general increase in particulates (both insoluble and soluble, starting around 1490 A.D. and ending abruptly in 1880 A.D.; (2) an initial increase in net accumulation (1500-1720 A.D.) followed by a period of decreased net accumulation (1720-1860 A.D.); (3) more negative delta-O-18 values beginning in the 1520's and ending around 1880 A.D. The "Little Ice Age" event is evident as a perturbation in all five ice core parameters.

400 years of precipitation variability in central and southern California reconstructed from tree-rings [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Precipitation variability at 31 stations hanging from San Diego to San Francisco and from the coast to the Sierras was characterized ...

Age and size composition, growth rate, reproductive biology, and habitats of the West Australian dhufish (Glaucosoma hebraicum) and their relevance to the management of this species

Samples of the commercially and recreationally important West Australian dhufish (Glaucosoma hebraicum) were obtained from the lower west coast of Australia by a variety of methods. Fish <300 mm TL were caught over flat, hard substrata and low-lying limestone reefs, whereas larger fish were caught over larger limestone and coral reef formations. Maximum total lengths, weights, and ages were 981 mm, 15.3 kg, and 39 years, respectively, for females and 1120 mm, 23.2 kg, and 41 years, respectively, for males. The von Bertalanffy growth curves for females and males were significantly different. The values for L∞, k, and t0 in the von Bertalanffy growth equations were 929 mm, 0.111/year, and –0.141 years, respectively, for females, and 1025 mm, 0.111/year, and –0.052 years, respectively, for males. Preliminary estimates of total mortality indicated that G. hebraicum is now subjected to a level of fishing pressure that must be of concern to fishery managers. Glaucosoma hebraicum, which spawns between November and April and predominantly between December and March, breeds at a wide range of depths and is a multiple spawner. The L50’s for females and males at first maturity, i.e. 301 and 320 mm, respectively, were attained by about the end of the third year of life and are well below the minimum legal length (MLL) of 500 mm. Because females and males did not reach the MLL until the end of their seventh and sixth years of life, respectively, they would have had, on average, the opportunity of spawning during four and three spawning seasons, respectively, before they reached the MLL. However, because G. hebraicum caught in water depths >40 m typically die upon release, a MLL is of limited use for conserving this species. Alternative approaches, such as restricting fishing activity in highly fished areas, reducing daily bag limits for recreational fishermen, introducing quotas or revising specific details of certain commercial hand-line licences (or doing both) are more likely to provide effective conservation measures.

One hundred years of rainfall trends in California

This paper is an examination of precipitation trends in California for 100 years based on 96 rain records. The study resulted from an attempt to develop a wetness index for the San Francisco Bay area, where declining rainfall trends indicated a lot more rainfall in the first 50 years of the study period. A regular pattern of decline was found in California coastal stations, concurrent with an increasing trend at inland stations.