The European Union (EU) has called for the relocation of aquaculture to the open seas, given the environmental problems created by some coastal marine farms.. But what is the impact of aquaculture on the high seas? A study from the University of Plymouth came to shed light on this issue.
Aquaculture is already an integral part of global food security. It represented 46% of the world’s total fish and shellfish production in 2018.It closes the gap in game fishing, which remains stagnant and cannot meet the increasing demand.
But There are concerns about the impact of this industry on the environment. Various studies have found that 37% of aquaculture production comes from coastal mussel farms from the coastal marine environment. decrease in fauna abundance and diversityas well as an increase in organic matter and fine sediments.
Therefore, the EU directive on marine spatial planning called for the relocation of aquaculture to the high seas. reduce environmental impactsolve space limitation problems in coastal areas and Meet the growing global demand for protein.
“Recently, it was determined that bivalve mollusc aquaculture provides one of the lowest-impact animal foods. Bivalve mollusc aquaculture requires very little energy input, has the lowest greenhouse gas output per serving of protein, absorbs nutrients, and requires virtually no fresh water or antibiotics.“, say the authors of the study on high-altitude aquaculture.
Molluscs, ‘carbon scavengers’
But there is more: bivalve aquaculture ‘holders’ carbonbecause these animals use that of the water to create calcium carbonate and therefore extract carbon from the ocean, which is “An important regulatory ecosystem service in the effort to mitigate climate change“, assemble the researchers.
This study, published in the journal ‘Aquaculture, Fish and Fisheries’, is part of the ‘The ecology of offshore mussel farms’ project and First long-term experimental ecological evidence that openwater mussel culture can have positive and restorative effects on degraded seabed habitats..
The investigation complements the investigation launched in 2008 to confirm the effects of the ban on bottom trawling. In 2013 he focused on Europe’s largest mussel farm in Lyme Bay, on England’s south coast. severely disturbed seabed For years with the bottom trawler.
Since the facility’s opening, scientists have used underwater cameras with towed and static baits for regular monitoring studies where they tested their effects on seafloor habitat and related species living on it.
In addition to growing on the farm, they found that mussel shells first invaded the seabed after six months, and much larger groups emerged in the first two years after the farm opened.
Increasing fish abundance
Both the size of the mussel clusters and the percentage of shell cover under the farm increased over time, which as a result the abundance of other species increases.
An example: amount of horse mackerel or mackerel (trachurus trachurus) More than 300% increase in farm environment in four yearscompared to other Lyme Bay areas.
they also registered notable increases in the number of lobster samples (Homarus gammarus) and crab (Cancer pagurus) are two commercially important species in Lyme Bay, but are not expected to be found in this region due to its high degradation.
“Over the last 15 years, we have consistently shown that: The ban on bottom angling has had a positive impact on the environment.. This study gave us the first ecological evidence. Offshore mussel farming can provide similar benefits in degraded seabed habitats.“underlines Emma Sheehan, director of the Lyme Bay monitoring project since 2008 and lead author of the study.
In addition to assessing the effects of the bottom trawling ban and offshore fishing, researchers have shown that: Limiting pot fisheries for crab and lobster provides long-term benefitsand this restored seafloor can recover more quickly after extreme storms.
The recommendations of this ongoing study are incorporated into the UK Government’s 25-Year Environment Plan.
Reference report: https://doi.org/10.1002/aff2.77
……..
Contact details of the environment department: [email protected]