The protected and slow-growing cold-water corals in the fjords of Norway are entangled in fishing gear. Worrying, say experts, as more or less all areas are impacted by fishing.
Coral reef in Skarnsundet, Trondheimsfjord. A fishing line can be seen in the corals. Photo credit: Johanna Järnegren, NINA.
The world’s shallowest cold-water coral reef is found in the Trondheimsfjord in Norway. These Lobelia reefs are regarded as hot spots for biodiversity and carbon cycling, and they play a key role in benthic ecosystems in Norwegian waters.
Following decades of human pressure from a variety of threats, the reefs have been protected from harmful bottom trawling. However, today’s regulations do not prohibit fishing or use of fishing gear in the marine protected areas (MPAs).
Old and slow growing
Using a remotely operated vehicle (ROV), a small underwater vessel, experts from the Norwegian Institute for Nature Research (NINA) and the Norwegian University of Science and Technology (NTNU) mapped the condition of the cold-water corals in the three MPAs Skarnsundet, Tauterryggen and Rødberget in the Trondheimsfjord.
Large parts of the corals in the MPAs appear to be in good condition, with clear exceptions. It is worrying that more or less all areas are impacted by fishing, says NINA senior researcher Johanna Järnegren.
Fishing net entangled in the corals in Skarnsundet MPA. Photo credit: Johanna Järnegren, NINA.
As cold-water corals have great longevity and grow slowly, the impacts accumulate over time, even if the impact from fishing with nets and lines are far less destructive than for example bottom trawling. It may take centuries to millennia for the corals to recover if they are destroyed, she says.
Need for strengthened protection
The study was conducted on behalf of the County Governor in Trøndelag, management authority in the area, in an attempt to avoid damage by fishing gear by knowing the exact location of the reefs.
However, deriving from the results of these investigations, it is recommended that the protection of the corals in the three MPAs in the Trondheimsfjord is strengthened, Järnegren concludes.
Want to learn more? Read the report here (Summary in English)
Contact: Johanna Järnegren