Bottom trawling decimating ocean life says report

Discarded bycatch species include undersized hake, sharks, skates, ribbonfish, dory and around 119 tonnes of mostly juvenile squid per annum, to name a few, said the report by WILDTRUST. Picture: Supplied

Discarded bycatch species include undersized hake, sharks, skates, ribbonfish, dory and around 119 tonnes of mostly juvenile squid per annum, to name a few, said the report by WILDTRUST. Picture: Supplied

Published Jun 16, 2024


Environmental NGO WILDTRUST, has put the spotlight on Demersal or “bottom trawling”, with a report showing the damage that is being done to marine life.

The fishing method uses weighted nets which are dragged along or near the seafloor. Although it is an effective way of sourcing protein from the sea, it is linked to all three of the major threats of fishing on marine life: overfishing, bycatch, and habitat damage.

WILDTRUST, in collaboration with Anchor Environmental Consultants, has released the “South African Inshore Demersal Trawl Fishery Assessment Report” which highlights the web of conflicts and challenges linked to the inshore hake trawl fishery and makes several recommendations on how to mitigate these and improve its sustainability.

“The South African inshore trawl fishery sector primarily targets hake and sole and faces numerous challenges due to overlaps with other commercial sectors and concerns about damage to biodiversity, impacts on habitats, as well as socio-economic consequences.

“Deep sea communities can take centuries to form, but when a trawler runs over them, they’re severely damaged or destroyed, and so is the whole community that had formed around them – as sea creatures can no longer use the habitats that previously provided them with shelter and food,” said Senior Scientist at the WILDTRUST, Dr Jennifer Olbers. “Unlike watching a forest on land being chopped down and seeing the impact – trawling happens out of sight and is therefore out of mind for many of us.”

The inshore trawl fishery is described as a “mixed” fishery meaning that in addition to hake and sole, a suite of other incidentally caught species are caught and discarded, including undersized hake, sharks, skates, ribbonfish, dory and about 119 tons of juvenile squid a year, to name a few.

WILDTRUST recommended that measures to curb some of the challenges include the establishment of Fisheries Management Areas and Priority Fishing Areas to manage overlaps effectively and strict bycatch limits and observer monitoring.

“Another potential solution is establishing trawl exclusion areas and additional Marine Protected Areas (MPAs) to safeguard livelihoods and preserve fragile ecosystems, as well as reduce the negative impacts of the inshore trawl fishery on Endangered, Threatened and Protected (ETP) species.

“To reduce the negative impacts of fisheries on Critically Endangered soupfin sharks, a Precautionary Upper Catch Limit (PUCL) for this species is suggested in the report to prevent overshoots of allowable catch, and a move-on rule for this species (fishing must cease in an area when a threshold is reached) is promoted.

To enhance accountability and improve compliance with regulations, the report suggests improving observer coverage, implementing real-time monitoring systems, and utilising technological advancements for more efficient data collection.

Given spatial overlaps and sharing of resources amongst commercial, small-scale and recreational fisheries, levels of bycatch and adverse habitat impacts, it is likely that the inshore trawl fishery could currently have an impact on coastal communities who depend on fishing for livelihoods and jobs within the tourism and hospitality industries.

“However, better understanding on current fishing practices and levels of exploitation within small-scale fisheries is required. Spatial conservation measures, e.g., new Marine Protected Areas, combined with enhanced cross-sector resource exploitation controls are likely to be the most effective management options, in some cases, to safeguard livelihoods of communities that are dependent on fisheries with which the inshore demersal trawl fishery conflicts.

“These recommendations, derived from extensive research and stakeholder consultations, provide a roadmap for enhancing the sustainability of South Africa's inshore trawl fishery,” commented Barry Clark of Anchor Environmental.

“By addressing conflicts, promoting responsible resource management, and safeguarding coastal communities, these measures strive to ensure a thriving marine ecosystem for future generations.”