Abstract
Pressure on deep-sea ecosystems continues to increase as anthropogenic activities move into ever deeper waters. To mitigate impacts on vulnerable habitats, various conservation measures exist, such as the designation of Marine Protected Areas (MPAs). So far, however, little evidence is available about their effectiveness. This paper presents a unique follow-up study assessing the status and recovery of a deep-sea fisheries closure and MPA at ~1000m water depth in the NE Atlantic, eight years after designation. The Darwin Mounds cold-water coral ecosystem was discovered in 1998, and closed to all bottom contact fisheries, especially trawling, in 2003. Our repeat survey in 2011 used both high-resolution sidescan sonar data collected by Autonomous Underwater Vehicle (AUV) and video footage from a Remotely Operated Vehicle (ROV) to evaluate recovery. The results demonstrate that (1) protection was successful and fishing impact was largely avoided in the Western Darwin Mounds, which contained similar proportions of live cold-water coral occurrence in 2011 as observed in 1998–2000; however (2) the Eastern Darwin Mounds suffered severe damage pre-closure, and by 2011 showed no coral recolonisation and very little regrowth. These results are further evidence for the low resilience and slow recovery potential of deep-sea ecosystems, and underline once again the importance of the precautionary principle in deep-sea conservation.
Highlights
The reduction was marked in the Eastern Darwin Mounds, the area most heavily impacted in 2000
The strong reduction in trawl mark density from 2000 to 2011 indicates that in general, the fishing community complies with the closure and the Marine Protected Areas (MPAs) designation
Even in the Darwin Mounds, some violation of the closure did occur, as illustrated by the two pairs of trawl marks found in the 2011 data
Summary
In addition to the physical damage, the indirect effects include biodiversity loss, community changes (Althaus et al, 2009) and coral smothering by resuspended sediment (Larsson and Purser, 2011) In several cases, these observations have triggered conservation measures, often based on temporary or permanent area closures. The restrictions may apply to either bottom trawling only, or to all bottom contact gear In general these closures seem fairly well respected (e.g. Armstrong and van den Hove, 2008), and in some cases are even developed by the fishing industry itself (e.g. Benthic Protection Areas offshore New Zealand; Helson et al (2010)), so far there is little information about recovery rates of the coral ecosystems. A repeat survey in 2011 provided the unique opportunity to evaluate the status of the cold-water coral habitat after eight years of protection, and gave insight in the recovery potential of a deep-water VME
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
