Continental slope and deep-sea fisheries: implications for a fragile ecosystem

Major impacts of climate change on deep-sea benthic ecosystems

“…CWC structures provide shelter from predation for a variety of fauna and, as such, can act as nursery grounds for commercially important species (Koslow et al, 2000, Baillon et al, 2012Henry et al, 2013). The habitat complexity of these biogenic reefs also leads to high levels of biodiversity on the reefs (Henry et al, 2007).…”

“…For example, oil and gas are currently being extracted to depths > 3000 m on continental margins, with increasing risk for leakage and spills (Cordes et al, 2016). Pressure from fishing has also increased since the mid-20 th century on seamounts and along continental margins, and there is now strong evidence that many deepwater fish species (e.g., rockfish, Greenland halibut, lings and tusks, orange roughy, sablefish and blue grenadier) have been severely exploited through trawling and longlining, with some species having been fished to commercial extinction (e.g., pelagic armourhead; Koslow et al 2000). There is also extensive interest in mineral mining at hydrothermal vent systems along mid ocean ridges and back arc basins, bathyal seamounts and polymetallic nodule areas at abyssal depths, as well as for phosphorites on margins (Mengerink et al, 2014;Thurber et al, 2014;Wedding et al, 2015;Amon et al, 2016;Levin et al, 2016;Vanreusel et al, 2016).…”

“…Although some animals (e.g., fishes) may be able to adapt to a limited degree to these anthropogenic stressors, for example, by accelerating their growth and reaching maturity at earlier ages (Koslow et al, 2000), the slow population growth rates and long generation times that characterize the evolution of many deep-sea organisms will ultimately limit their adaptation to stress. Additional stresses imposed by low O 2 , low pH, elevated temperature and reduced food supply are likely to further reduce the resilience of individual species and ecosystems to anthropogenic stressors, and slow rates of recovery.…”

Montes submarinos de Nazca y Salas y Gomez: una revision para el manejo y conservacion

“…De acuerdo con Butler et al (2001), el efecto de la remoción de gran número de predadores tope en ecosistemas de profundidad es escasamente conocido. Koslow et al (2000) indican que las dudas más importantes son en relación a las implicancias ecológicas de largo plazo en el agotamiento de especies de nivel trófico medio-alto en ecosistemas de aguas profundas y el impacto sobre las poblaciones de predadores y presas, y que para estos cuestionamientos actualmente hay pocas respuestas. No obstante, recientes estudios (Morato et al, 2004(Morato et al, , 2006, basados en la historia de vida y las características ecológicas de las poblaciones que tradicionalmente habitan los MS, probaron la hipótesis que las poblaciones de peces de los MS generalmente tienen un mayor nivel de vulnerabilidad a la pesca, y que esta vulnerabilidad está correlacionada con sus parámetros poblacionales.…”

Why are Brazilian deep demersal fish resources valuable? An analysis of the size of edible flesh and its chemical composition

“…Because deep ecosystems are generally food-limited, deep water species were shown to be less productive and less resilient than shallow-water species, hence clearly not capable to replace economic losses at overfished continental shelves (Norse et al, 2012). Nonetheless, important trawl fisheries have persisted in deep areas of the Pacific, Atlantic, Indian and Southern oceans as driven by aggregation patterns of some fish stocks, economic subsidies to the fishing industry and the high value sometimes attributed to commercial deep-water species (Koslow et al, 2000;Gianni, 2004;Norse et al, 2012).…”