HALIEUTIQUE MER ET LITTORAL

Marine megafauna are increasingly threatened and are difficult to protect. Understanding the influence of humans on body size in fishes is also challenging given that data on marine species often come from fishery-based activities. Letessier et al. deployed more than 17,000 remotely operated baited devices to collect data on fish size and abundance as related to habitat (pelagic or benthic), human activities, and marine protected areas. Pelagic species were strongly influenced by human pressures and protection. The authors concluded that benthic species could be effectively protected even near markets, whereas only more remote protected areas will effectively safeguard large pelagic species.

Source : Sacha Vignieri (Science)

Coral reefs are among the most biodiverse systems in the ocean, and they provide both food and ecological services. They are also highly threatened by climate change and human pressure. Cinner et al. looked at how best to maximize three key components of reef use and health: fish biomass, parrotfish grazing, and fish trait diversity. They found that when human pressure is low, all three traits can be maximized at high conservation levels. However, as human use and pressure increase, it becomes increasingly difficult to promote biodiversity conservation. At some levels of human impact, even the highest amount of protection is not able to maximize biodiversity conservation.