麻豆淫院

Sea life on the seafloor of New Zealand's most productive and important commercial fishing ground shows resilience to disturbance, according to a new study in the New Zealand Journal of Marine and Freshwater Research.

The research found that some aspects of seafloor ecosystems on the Chatham Rise showed an ability to recover relatively quickly from physical disturbances, such as those caused by seafloor mining and trawling.

The research suggests that the seafloor ecosystem of the Chatham Rise may be more resilient to disturbances than previously thought, says NIWA marine ecologist Dr. Rachel Hale, lead author for the study. "This resilience may be due to the region's history of natural and human disturbances, which has led to the dominance of opportunistic species.

"While our results are encouraging, it's important to note that there were some post-disturbance changes in the environmental characteristics that were measured. These changes, particularly in the composition of seafloor communities, may have longer-term repercussions for ecosystem processes."

Researchers disturbed an area of seafloor on the Chatham Rise and monitored the impacts on sediment, seafloor-dwelling aquatic animals, and took measurements of oxygen and nutrient fluxes, and bacterial abundance.

They found disturbance changed the sediment composition, reducing food quality, and initially reducing the diversity of seafloor-dwelling aquatic life, though after a year some of the aquatic life had bounced back. Contrary to expectations, the disturbance didn't result in significant changes to the nutrient levels, and the rapid recolonization of the seabed saw bacteria levels recover.

The study revealed the resilience of the sea floor to disturbance, but also highlights potential long-term changes that need more investigation, says Dr. Hale. "Expansion of extractive industries to deep-sea environments will lead to increased stresses on seafloor ecosystems. Further long-term studies are required to fully understand the potential impacts of disturbance on sediment processes, nutrient cycling, and the overall health of the Chatham Rise ecosystem."

The Chatham Rise is a large area of ocean floor around 1,400km east of New Zealand which stretches some 1,000 km long. The underwater plateau, accessible to trawling, provides about 60% of New Zealand's fish catch, including hoki, hake, ling, warehou, squid, orange roughy and deep-sea dory. Data from research has enriched models and enabled long-term monitoring, with NIWA undertaking surveys since 1992 on fisheries and ecosystems.