Collisions take heavy toll on sea creatures

A struck whale can be carried unnoticed far from the site of the collision. Image: SAVE COASTAL WILDLIFE

A new scientific report has revealed that at least 75 different ocean species are killed in collisions with boats and ships.

The report, compiled by a team of scientists including Port Elizabeth-based marine biologists Renee Schoeman and Dr Stephanie Plön,  is the first to consider the impact of vessel traffic on all marine life, and not just whales and dolphins, which is already well documented.

Claire Patterson-Abrolat of the Endangered Wildlife Trust, the third member of the team, said the findings revealed the sometimes horrific injuries to individual animals and the possible impact on entire populations because of slowed reproduction rates — and shone a light on the way forward in a critical period.

“Oceans provide valuable recreational and transport services and the importance of these should be central to the rebuilding of our oceans economy,” she said.

“If nothing else, Covid-19 has provided us with a valuable opportunity to reflect on our past actions and to build an economy that truly considers its impact on the environment but that also ensures the prosperity of humankind.”

The report, published in the latest edition of the international journal Frontiers of Marine Science, did not rely on new studies but collated and analysed all available literature on the subject.

Patterson-Abrolat said their research revealed a serious situation with a number of negative effects.

“The collisions occur far more regularly than previously thought.

“At least 75 different marine species — ranging from whales to dolphins, sharks, sea otters, seals, penguins and sea turtles — have been recorded as being killed though collisions with ships.

“It’s not just large commercial vessels that are responsible but small recreational vessels, too.

“Injuries range from minor to horrific with deep lacerations, fractures, haemorrhaging, amputated body parts such as fins or tails, and even death.”

She said it was not just the animals that came off badly.

“Vessels may incur damage such as cracked hulls or broken propellers.

“In a few cases, the ship’s crew can also be injured, with extreme cases resulting in being knocked overboard and loss of life.”

Addressing possible solutions, Patterson-Abrolat said temporary rerouting of ships during breeding seasons could reduce the risk of collisions but this needed to be considered for all vulnerable species and not just whales which was where the strategy was focused at present.

Mandatory reporting of collisions, early warning systems, trained observers on board, deterrent devices and propeller guards could all help.

Over and above this a centralised database of all collisions needed to be developed to allow for the identification of potential hotspots, and research on the correlation between collision injuries and population changes was needed, she said.

“It should also ascertain if there is any way of determining when smaller species have been involved in a collision, and how to identify high-risk areas for all species.

“Enforcement should be stepped up where necessary to ensure adherence to speed reduction zones, and education and awareness materials should be made available to ship crews, and recreational skippers.”

Plön, from the Bayworld Centre for Research and Education, said data collected from strandings of whales and dolphins over the years in and around Algoa Bay had showed that vehicle collisions were definitely a factor in some deaths but further analysis was needed and broader statistics were not at this stage available.

“But the expansion of the Port of Ngqura and offshore bunkering which has drawn more ships into the bay is in line with the increasing industrialisation of our ocean which is behind the high collision rate internationally.

“We sit on a global biodiversity hotspot here in Algoa Bay with a rich array of marine animals and all our human role players need to sit down together to find innovative solutions to prevent this happening in our waters.”

By Guy Rogers

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