Africa-Press – South-Africa. An algae bloom triggering a massive lobster walkout on the West Coast could put an already strained population of West Coast lobster under even more stress.
The Department of Forestry, Fisheries and the Environment (DFFE) activated its West Coast Rock Lobster Contingency Plan this week and issued a Situation Red Alert following a harmful algal bloom that caused around five tons of West Coast rock lobster to walk out.
“Department officials, together with the local municipalities and law enforcement, are working together to assist in rescuing live lobsters and with clean-up operations,” the DFFE said in a statement.
“The department will also work closely with the local communities in assisting with the beach clean-up and recovery of live West Coast rock lobster washed up due to the red tide.
“All recovered live lobster will be rehabilitated and will be safely returned to sea once the red tide threat has abated,” it added.
The DFFE said that there had been a build-up of red tides in the St Helena Bay region over the past few weeks, which had predominantly affected Elands Bay, Lambert’s Bay, and Doring Bay.
The department warned the public not to collect and consume the lobster because doing so could pose a serious health hazard.
Senior manager of World Wide Fund for Nature (WWF) South Africa’s marine programme, Craig Smith, said algae blooms were common during summer and could draw oxygen from the water. This sees animals such as lobster moving to the surf zone, where the waves have aerated the water, for relief. However, in the surf zone, they easily become stranded.
Smith believes the walkouts have increased in frequency over the last 50 to 100 years. He believes this could be linked to shipping activity.
“Some of the species in the phytoplankton are not native to South Africa. They typically catch a ride with ships in their ballast water and, with increased shopping activity, are more likely to be spread around the ocean when ships discharge their ballast water,” he said.
While there is no way to “fence in” the phytoplankton, Smith says ships can be encouraged to discharge their ballast water outside of sensitive coastal zones.
He added that managing the walkouts are key to preventing widescale population losses.
“We need to have an early warning system in place. Then you can get there early enough to rescue the lobsters and transport them to a different area,” he said.
“This way, you can limit the impact on a resource that is already compromised.”
To contextualise the amount of lobster that walked out this week, Smith said the total allowable catch (TAC) of West Coast rock lobster was around 500 tons a year.
“So, 1% of the TAC is already compromised. This doesn’t get deducted from the TAC,” he said.
Smith added that every stressor the population is exposed to has potentially devastating consequences.
“The population is at 1.6% of its pristine biomass levels. It’s really compromised and really vulnerable. The walkout adds to the pressures facing the population,” he added.
Patrick Dowling, Western Cape chairperson of the Wildlife Environment Society of South Africa (Wessa), said the algae bloom and subsequent walkout was a “natural phenomenon” that was regularly recorded over decades.
He said that while the walkout was not as large as those recorded previously, it could be a reflection on the poor health of the population rather than the marine conditions.
Dowling said the walkout could have been larger if the “resource was not so heavily depleted”.
“The sustainability of the west coast lobster (crayfish) fishery (currently at not more than 5% of historical levels) is a matter of serious environmental and economic concern that cannot, in our view, be solved politically,” he said.
Carmen Mannarino, programme manager at Masifundise, said the red tide has a major impact on the livelihoods of small-scale fishers on the West Coast, who have already seen reductions in the TAC every year due to the state of resources.
“We urge the Department of Forestry, Fisheries and the Environment to find a long-term solution to address this issue. West Coast rock lobster is a major source of income for small-scale fishers on the West Coast and a crayfish walk out of this scale causes further distress for their ability to put food on the table,” Mannarino added.
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