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Fishers' involvement is crucial. Image: WDC/JTF

When porpoises and people overlap

We're funding a project in Hong Kong that's working with fishing communities to help save...

Mindful conservation – why we need a new respect for nature

'We should look at whales and dolphins as the indigenous people of the seas -...
A dolphin called Arnie with a shell

Dolphins catch fish using giant shell tools

In Shark Bay, Australia, two groups of dolphins have figured out how to use tools...
Common dolphins at surface

Did you know that dolphins have unique personalities?

We all have personalities, and between the work Christmas party and your family get-together, perhaps...
Leaping harbour porpoise

The power of harbour porpoise poo

We know we need to save the whale to save the world. Now we are...
Holly. Image: Miray Campbell

Meet Holly, she’s an incredible orca leader

Let me tell you the story of an awe-inspiring orca with a fascinating family story...
Humpback whale. Image: Christopher Swann

A story about whales and humans

As well as working for WDC, I write books for young people. Stories; about the...
Risso's dolphin at surface

My lucky number – 13 years studying amazing Risso’s dolphins

Everything we learn about the Risso's dolphins off the coast of Scotland amazes us and...
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  • End captivity
  • Prevent deaths in nets
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  • Strandings

Minke whale hunts stop in Iceland

Iceland’s commercial hunt of minke whales has ended for this year. The common minke whale is the...
Port River dolphins

New report reveals 100,000 dolphins and small whales hunted every year

When you hear the words ‘dolphin hunts’ it’s likely that you think of Japan or...

End the whale hunts! Icelandic fin whaler isolated as public mood shifts

Here’s a sight I hoped never again to witness. A boat being scrubbed and repainted...

Australian Government to block Japanese whaling proposal

Japanese Government officials have reportedly confirmed that they will propose the resumption of commercial whaling...

Pregnant whales once again a target for Japanese whalers

Figures from Japan's whaling expedition to Antarctica during the 2017/18 austral summer have revealed that...

Did Icelandic whalers really kill a blue whale?

*Warning - this blog contains an image that you may find upsetting* They say a...

Icelandic whalers breach international law and kill iconic, protected whale by mistake

Icelandic whalers out hunting fin whales for the first time in three years appear to...

Doubts remain after Icelandic Marine Institute claims slaughtered whale was a hybrid not a blue

Experts remain sceptical of initial test results issued by the Icelandic Marine Institute, which indicate...

Japan set to resume commercial whaling

Reports from Japan suggest that the government they will formally propose plans to resume commercial...

Norway increases whaling quota despite declining demand

Norway's government has announced an increase in the number of minke whales that can be...

Icelandic fin whale hunting to resume

Iceland’s only fin whaling company, Hvalur hf,  announced today that it will resume fin whaling...

SOS alert for whales off Norway!

I have to admit to bitter disappointment when I arrived in Tromsø, northern Norway, a...

West African bycaught dolphins provide insights for new method for health assessment

Winners of the 2016 WDC Bharathi Viswanathan Award, Marie-Francoise Van Bressem and colleagues, studied photographs of dolphins bycaught in fishing gear from three Ghanaian ports, to develop an opportunistic, non-invasive research tool to examine epidemiological aspects of the general health of free-ranging and by-caught cetaceans. Read more about this novel research here and if you are interested in applying for the 2017 Award please submit your application by mid-day (GMT) April 24th 2017.

An initial visual assessment of general health of small cetaceans from West Africa

by Marie-Francoise Van Bressem, Joseph Debrah, and Koen Van Waerebeek

Several species of small cetaceans, including the common bottlenose dolphin (Tursiops truncatus), common dolphin (Delphinus sp.), Clymene dolphin (Stenella clymene), pantropical spotted dolphin (Stenella attenuata), spinner dolphin (Stenella longirostris), melon-headed whale (Peponocephala electra), short-finned pilot whale (Globicephala macrorhynchus), rough-toothed dolphin (Steno bredanensis), Atlantic humpback dolphin (Sousa teuszii) and harbour porpoise (Phocoena phocoena) are suffering significant mortalities in fisheries off Mauritania, Senegal, Ghana, Nigeria and Cameroon. However, very little is known of the other factors that could negatively affect their survival and reproductive fitness, including diseases and traumata. In this context we have so far examined images of 148 delphinids, belonging to 13 species landed at three Ghanaian ports between 1998 and 2016, and photos of a number of free-ranging short-beaked common dolphins  off Northwest Africa and short-finned pilot whales off La Gomera, Canaries, for the presence of traumas, deformations, skin disorders and commensal phoronts .

Generally, in comparison to other ocean provinces, it was striking how few skin disorders and other macroscopically visible health conditions affected West African small cetaceans.  

Ghanaian fishing ports (Axim, Dixcove, Apam from W to E) where the dolphins examined in this study were landed.


Pale skin patches of unknown aetiology, highly prevalent in Peale’s dolphin (Lagenorhynchus australis) in polluted waters from Chilean Patagonia[1], affected the dorsal fin of a single free-ranging common dolphin and a pilot whale, so prevalence here was low. 

Pale skin patch, partly ulcerated, in a short-beaked common dolphin free-ranging off Northwest Africa.


Cookie-cutter shark (Isistius sp.) bites were observed in 10 species of by-caught odontocetes with prevalence levels varying between 12 % in pantropical spotted dolphins and 61% in rough-toothed dolphins. Interestingly, these data increase the documented species distribution range of Isistius spp. into the waters of the northern Gulf of Guinea. 

Cookie-cutter shark bite scars in a melon-headed whale.


Miscellaneous other scars were seen in nine individuals landed in Ghana and, in four cases, were regarded as caused by fisheries interactions, including a large star-shaped scar in a Clymene dolphin, possibly resulting from a dislodged hand-held harpoon. Very similar scars have been seen also in Peruvian dolphins where harpooning is also commonplace. Evidently anthropogenic traumatic injuries, mainly from fisheries, may have an impact on the health, survival and welfare of West African dolphins. 

Large scar possibly from an old harpoon wound in a Clymene dolphin.        

An adult rough-toothed dolphin landed in Ghana had several skin nodules, some possibly ulcerated, on its back and dorsal fin, and a pantropical spotted dolphin in poor body condition,showed a medium-sized noduleon its right flank. Known aetiologies of skin nodules and granulomas in cetaceans include fungi (Trychophyton sp., Fusarium sp. and Paracoccidioides brasiliensis), bacteria (Streptococcus iniae and Pseudomonas spp.), papillomaviruses and macro-parasites (Anisakis spp.). Dozens of herpesvirus-like black skin lesions were observed on the body of a common bottlenose dolphin, butaetiology could not be examined. Also, poxviral tattoo skin lesions could not be positively identified in any species. Deformities, severe emaciation, commensalphoronts or ectoparasites were not detected in any of the species.

The present study further highlights the usefulness of good photographs of individual dolphins as an opportunistic, non-invasive research tool to examine epidemiological aspects of the general health of free-ranging and by-caught cetaceans. It provides a preliminary insight into the prevalence of a variety of cutaneous disorders, shark bites and other traumatic injuries affecting west African cetaceans and can help steer future, dedicated, research. In general, this technique may improve documentation of both natural and anthropogenic threats faced by cetaceans and may help to better understand their conservation status. 

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[1] Sanino GP, Van Bressem M-F, Van Waerebeek K, Pozo N (2014) Skin disorders of coastal dolphins at Añihue Reserve, Chilean Patagonia: a matter of concern. Bol Museo Nat Hist Nat, Chile 63: 127-158.