Is an octopus fishery hurting Mossel Bay's whales?

An investigation is underway to find out why three Bryde’s whale have died in Mossel Bay recently.

The Department of Environmental Affairs (DEA) and the Department of Agriculture‚ Forestry & Fisheries (DAFF) will be monitoring the situation.

"Measures will be put in place to address identified causes‚" the departments said.

Bryde’s whales have two different forms; one that occurs offshore and the other one inshore. The latest assessment of the species by the Endangered Wildlife Trust (EWT)‚ classified the inshore form as “Vulnerable” and the offshore form as “Data Deficient”.

The total population size remains unknown but a study of the inshore form off Plettenberg Bay on the South Coast of South Africa estimated between 125 and 195 individuals.

"This indicates that the number of whales are low and the mortality of one individual is therefore one too many‚" the environmental affairs department said in a statement sharing its concern.

The DEA said there is currently "a perception" that the Experimental Octopus Fishery may have contributed to the deaths.

Although this needed to be probed‚ the department said‚ "as the octopus fishery make use of lines and buoys that have the potential to entangle whales‚ ongoing attention is being given to the octopus fishery’s gear design to limit possible whale entanglements."

Concerns around this fishery‚ including gear designs‚ were already discussed at a stakeholder workshop coordinated by DAFF in June 2017.

"The experimental nature of this industry means stakeholder engagements are ongoing and all concerned parties should approach DAFF for further industry specific queries and DEA can be contacted if any whales are observed that are entangled‚ including in fishing gear. . .

"DAFF will‚ with the assistance of DEA and all roleplayers‚ continue to monitor this experimental fishery closely. Mitigation measures will be implemented as the need arises."

Other potential causes of death might include ship strikes‚ other type of fishing gear or of natural nature‚ the environmental affairs department noted.

Samples from two of the three recent whale strandings have been collected. Consultations are under way with local and international experts.

"These results will help to identify the possible causes of death for the whales stranded at Mossel Bay and will help to inform management interventions‚ where necessary‚" the department stated.