Susannah Calderan on whales and ship strikes in Sri Lanka
By Naveed Rozais
Being hit by ships can lead to whales being severely injured or even killed. This month’s public lecture by the Wildlife and Nature Preservation Society of Sri Lanka (WNPS) focuses on the topic of large whales and the risks posed to them by large ships. Speaking on the issue at the WNPS public lecture is marine mammal ecologist and Scottish Association for Marine Science Honorary Research Fellow Susannah Calderan.
Calderan specialises in acoustic studies on whales and the impact of human activities on whales such as ship strikes, underwater noise, and fisheries bycatch. Her work in acoustics has involved several Antarctic and sub-Antarctic research projects investigating blue whales, with the British Antarctic Survey and Australian Antarctic Division. She has been involved in blue whale research in Sri Lanka for several years, with a primary focus on resolving the blue whale ship strike problem, carrying out research with the University of Ruhuna.
In an interview with The Morning Brunch, Calderan explained that Sri Lanka’s coastline is very biologically productive, and the shipping lines run right through this biologically productive area, posing risks not just to the whales that frequent this area, but also to humans.
“Sri Lanka has very busy shipping lanes and is one of the biggest areas in the world for ship strikes because there are lots of ships and whales in a concentrated biologically productive area.”
Calderan further explained that because the shipping lines are not very wide, there is not a lot of space for ships to be able to avoid hitting things, thus also posing a risk to human life because this biologically productive area attracts lots of fishing boats and whale-watching boats. Particularly at night when there is little visibility, it is very easy for a large ship to hit one of the small fishing boats and not even know.
With regard to whales, being hit by ships can often be life-threatening, resulting in being badly injured and a lot of the time dying because of their injuries.
“It is usual that whales die when struck by ships. We don’t really know because we never see the dead whales. The coastal current carries them offshore. The ships might not even know they’ve struck a whale. From the whales that do wash up, and where we’re able to see how they’ve been killed, mostly the death is the result of ship strikes. It’s difficult to tell sometimes because a lot of the injuries whales receive when struck by ships are internal,” Calderan shared.
Working with the University of Ruhuna, Calderan has carried out in-depth research on how to solve the problem of ship strikes off the Sri Lankan coast.
“The main solutions to ship strike problems are either getting ships to slow down because the impact of a ship strike is worse when ships are faster, or to move the shipping lane. Ships are happier to move lanes rather than slow down. The research we conducted was on how far offshore we’d have to move the shipping lines and what reduction in risk that would bring about.”
Calderan’s research showed that moving the shipping lanes just 15 miles offshore minimises risk to whales by 95%, in addition to it being safer for fishermen pursuing their livelihoods. She shared that the shipping industry is keen to move shipping lanes, adding that 25% of ships no longer use these lanes and have moved offshore. “They would like more shipping lanes because when they’re offshore with no shipping lanes there’s no traffic control.”
On moving the shipping lanes, Calderan shared that shipping lanes are usually determined by the International Maritime Organisation (IMO), but that the IMO does not have the authority to change shipping lines unless officially requested to do so by the country to whom the shipping lanes belong.
Sri Lanka has unfortunately not made any requests. “We’ve been trying to do this for a few years, but there is really no interest among government officials. We’re not entirely sure why.”
On a personal level, Calderan feels this may be partly because they don’t want things to change for the possibility that going offshore may harm business at the Colombo and Southern ports and that ships will be less likely to stop in Sri Lanka if the lanes are moved. Calderan pointed out that this would not be the case because ships plan their routes very carefully well in advance and they would only stop in Sri Lanka if they were planning to do so in advance. Spontaneous stopping at ports is very rare, and Calderan doesn’t think the economy will be impacted if lanes go offshore.
Other countries have made similar changes to their shipping lanes. Calderan shared that the US, for example, moved their shipping lanes on the East and West coasts because of whales being struck. Panama has also moved their lanes, as have quite a few places in the world.
“The good thing about Sri Lanka is that it would be easy to move lanes because you just have to move them offshore. There’s a drop off in depth and you don’t find whales off the coast. Other places can be more complicated because whales are everywhere and that can make positioning lanes quite difficult.”
Calderan stressed that the most effective thing to do to fix the issue is to move the shipping lanes. “The research we did gave us such clear results that there was a very good solution. Scientists will always tell you that they need more data and more research, but in this case, we’re in the unusual situation of it being quite clear what needs to be done. We can’t restrict the number of ships, or move the whales or the fishermen. Slower speeds are very unpopular and the ships would need to slow down for a long way which would really impact efficiency. It wouldn’t reduce risk in the same way. We have a very good, very easy solution, but we just need for it to be taken up within the Sri Lankan Government.”
As with many issues related to wildlife and the environment, there is a tendency to gloss things over and treat it as non-critical.
“We’re often told that there isn’t enough proof that there is a problem, but even if the problem isn’t as large as we think, it’s still a problem and moving the lanes would be an easy thing to do. It’s also what the shipping industry themselves want,” Calderan said.
Susannah Calderan will be discussing blue whales and ship strikes off Sri Lanka’s coast in detail at this month’s WNPS public lecture on 10 December at 6 p.m. via Zoom and Facebook Live.