Antarctic krill, Euphausia superba, supports a valuable commercial fishery in the Southwest Atlantic, which holds the highest krill densities and is warming rapidly. The krill catch is increasing, is concentrated in a small area, and has shifted seasonally from summer to autumn/winter. The fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources, with the main goal of safeguarding the large populations of krill-dependent predators. Here we show that, because of the restricted distribution of successfully spawning krill and high inter-annual variability in their biomass, the risk of direct fishery impacts on the krill stock itself might be higher than previously thought. We show how management benefits could be achieved by incorporating uncertainty surrounding key aspects of krill ecology into management decisions, and how knowledge can be improved in these key areas. This improved information may be supplied, in part, by the fishery itself.
Survey of yellowfin tuna in the west-central Indian Ocean was conducted on board of Chinese longliners during 2003, 2004 and 2005, which is a part of Chinese Tuna Fishery Scientific Observer Program (CTFSOP).The reproductive biology has been investigated. A total of 1 023 samples are collected including 417 ovaries and 606 testes. Spawning activities of yellowfin tuna have been studied for both male and female from January to June. The data showed that the average monthly sex ratio is 0.59, and the minimum length at sexual maturity is 101 cm for female and 110 cm for male respectively. Length at 50% sexual maturity is estimated at 113.77 cm for female and 120.20 cm for male, whereas maturation rate is 0.066 cm -1 for female and 0.091 cm -1 for male. Sex ratio by length class indicates that the proportion of male is higher than female's along with size increasing; for instance, in the group of the body length longer than 145 cm, some females have their body length from 145 to 160 cm and males have their body length at 160 cm and even longer. Statistically, yellowfin tuna has a significant seasonal reproduction.
Data from the Dongguan Eye Study provide information concerning the prevalence, risk factors and impacts of eye diseases in rural residents undergoing urbanization in southern China.
Chronic exposure to ultraviolet B (UVB) irradiation is a major cause for skin photoaging. UVB induces damage to skin mainly by oxidative stress, inflammation, and collagen degradation. This paper investigated the photo-protective effects of peptides from oyster (Crassostrea hongkongensis) protein hydrolysates (OPs) by topical application on the skin of UVB-irradiated mice. Results from mass spectrometry showed that OPs consisted of peptides with a molecular weight range of 302.17–2936.43 Da. In vivo study demonstrated that topical application of OPs on the skin significantly alleviated moisture loss, epidermal hyperplasia, as well as degradation of collagen and elastin fibers caused by chronic UVB irradiation. In this study, OPs treatment promoted antioxidant enzymes (SOD and GPH-Px) activities, while decreased malondialdehyde (MDA) level in the skin. In addition, OPs treatment significantly decreased inflammatory cytokines (IL-1β, IL-6, TNF-α) content, and inhibited inflammation related (iNOS, COX-2) protein expression in the skin. Via inhibiting metalloproteinase 1(MMP1) expression, OPs treatment markedly decreased the degradation of collagen and elastin fibers as well as recovered the altered arrangement of extracellular matrix network in the dermis of skin. Our study demonstrated for the first time that OPs protected against UVB induced skin photodamage by virtue of its antioxidative and anti-inflammatory properties, as well as regulating the abnormal expression of MMP-1. The possible molecular mechanism underlying OPs anti-photoaging is possibly related to downregulating of the MAPK/NF-κB signaling pathway, while promoting TGF-β production in the skin.
Sixty-nine fish species belonging to 41 genera from 29 families and seven orders were collected during 2006-2007 by otter trawl in Beibu Gulf, northern South China Sea, for analysis of their length-weight relationships (WLRs). The analysis included 19 species for which no previous WLR estimates were available in FISHBASE.
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