Stylasterid coral community dynamics in the Larsen area, east Antarctic Peninsula

The eastern Antarctic Peninsula is characterized by large-scale disintegrations of the Larsen A and B ice shelves in 1995 and 2002, respectively, widely viewed as consequences of global warming. Stylasterid communities of the Larsen A and B embayment in the eastern Antarctic Peninsula were investigated to obtain information regarding their role in the Antarctic benthic ecosystem and their response to large-scale ice-shelf disintegration. The study compares video and photo transects of the expeditions with the RV Polarstern in 2007 and 2011. Data allowed temporal as well as spatial analyses and comparison of the stylasterid communities. The analyses include the identification and distribution of species, abundances, growth and quantification of branching patterns. Errina gracilis was found to be the most abundant species in the Larsen A and B area. Two other species of Errina were present along with one species of Inferiolabiata. The diversity of stylasterids was found to be greater in the Larsen B area, but the densest accumulations were found in the southern part of the Larsen A area. An increase in 86 % of abundance was observed in this area and a linear growth of the colonies of 3 mm within 4 years. In addition, a positive correlation between coral size and branching patterns was found, which facilitates the future analysis of coral size using video or photographic material without a reference scale. For conservation and protection purposes of Antarctic benthic ecosystems, an understanding of organisms and processes is needed. However, only very few studies focus on the diversity of Antarctic stylasterid corals

Reducing cod bycatch in flatfish fisheries

Accepted manuscript version, licensed CC BY-NC-ND 4.0. Management measures to facilitate the recovery of fish stocks can lead to shifts in traditional fishing patterns and target species. In the Baltic Sea, drastic reductions in catch quota for cod (Gadus morhua) force mixed demersal trawl fisheries to avoid cod bycatch and focus on flatfish species. This study developed and tested a simple se- lection concept that aims to avoid cod bycatch in flatfish-directed trawl fisheries by removing a section of the top panel from the extension piece of the trawl (roofless concept). Sea trials testing the performance of a baseline roofless design, and two designs intended to enhance escape reactions of cod were conducted during two sea cruises. Analysis of the resulting catch data revealed that applying the baseline roofless design consistently reduced cod bycatch by ~75%. Catches of the target species plaice (Pleuronectes platessa) and flounder (Plati- chthys flesus) were reduced by less than 15%; however, we estimated that catch losses of the two flatfish species could be balanced by increasing fishing effort to ~8% and ~12%, respectively. None of the two roofless designs, intended to enhance escape reactions on cod, improved the performance of the baseline design. Under the scenario of fishery choke caused by limited cod quotas, we estimated that the use of the baseline roofless concept could increase fishing possibilities for flatfish by more than 300

Reducing cod bycatch in flatfish fisheries

Accepted manuscript version, licensed CC BY-NC-ND 4.0. Management measures to facilitate the recovery of fish stocks can lead to shifts in traditional fishing patterns and target species. In the Baltic Sea, drastic reductions in catch quota for cod (Gadus morhua) force mixed demersal trawl fisheries to avoid cod bycatch and focus on flatfish species. This study developed and tested a simple se- lection concept that aims to avoid cod bycatch in flatfish-directed trawl fisheries by removing a section of the top panel from the extension piece of the trawl (roofless concept). Sea trials testing the performance of a baseline roofless design, and two designs intended to enhance escape reactions of cod were conducted during two sea cruises. Analysis of the resulting catch data revealed that applying the baseline roofless design consistently reduced cod bycatch by ~75%. Catches of the target species plaice (Pleuronectes platessa) and flounder (Plati- chthys flesus) were reduced by less than 15%; however, we estimated that catch losses of the two flatfish species could be balanced by increasing fishing effort to ~8% and ~12%, respectively. None of the two roofless designs, intended to enhance escape reactions on cod, improved the performance of the baseline design. Under the scenario of fishery choke caused by limited cod quotas, we estimated that the use of the baseline roofless concept could increase fishing possibilities for flatfish by more than 300