On today’s episode of Ocean Talk Friday, Andrew and I wrapped up the week by discussing “dolphin-friendly” labeling, vessel identification numbers, humpback whale migrations, and fish camouflage strategies.
- The fight for reducing dolphin bycatch
This week, the World Trade Organization (WTO) ruled that the United States’ ban on imports of specific tuna creates an unfair barrier to international trade. This is a long and complicated story, but essentially the United States has taken measures over the last couple of decades to reduce dolphin mortality caused by tuna fishing. The country has enacted a voluntary “dolphin-friendly” label on tuna products that were caught using nets and methods deemed safe for dolphins, and banned tuna imports caught with unsafe methods. However, a few years back Mexico challenged this ban by claiming that the U.S. is unfairly restricting tuna imports from Mexico. While Mexican tuna fishers do take steps to prevent dolphin bycatch, they do abide by the steps the U.S. requires, meaning they cannot sell their tuna to the States. The WTO, for the fourth time in the last four years, has agreed with Mexico. While the doesn’t necessarily mean the U.S. will have to lower the “dolphin-friendly” label’s standards or do away with it completely, it does mean the U.S. will have to return to the drawing board and work together with Mexico to ensure fair trade occurs between the two neighboring countries.
- Tracking fishing vessels at sea
While we’re on the subject of fishing vessels, did you know that we currently do not have any formal international tracking policy for these ships? Well, the Pew Charitable Trust group is working towards implementing one. They are calling for the International Maritime Organization and the Food and Agriculture Organization of the United Nations to collaborate on establishing a unique and permanent identification number for all of the 185,600 large commercial fishing vessels (over 24 meters or 100 gross tons) currently in operation. Not only will this system make it easier to track and identify illegal fishing practices, it will also help inform effective management of our marine habitats. By understanding where commercial fishing vessels most frequently operate, we can better inform and protect depleted stocks and the fishing industry.
- Spot the humpback tail
Do you enjoy sailing your yacht down to the Caribbean every few weeks just to unwind? I know Andrew and I certainly do. Well, now you can also contribute to our knowledge of humpback whale migrations while you’re down there. A new website called Caribtails.org lets boaters in the Caribbean photograph and upload images of humpback whale flukes (tail fins). Researchers will then run these images through their identification database to track individual whales’ movements from the Caribbean breeding zones to the North Atlantic feeding grounds. As is the case with vessel ID numbers, more data on the migration patterns of these whales will help researchers and policy makers better understand and protect these charismatic megafauna.
- Fish camouflage techniques in the open ocean
Small open ocean fish have a rough life. They basically just exist to be prey for other, larger species. However, since the biological goal of every species is to live long enough to reproduce, you would think that these fish have developed some protection from open ocean predators. Well, researchers out of UT Austin may have found this protection. By recording the interactions of different types of light with the scales of open ocean fish, Dr. Brady and his team found that these common prey items reflect polarized light (frequently found in the ocean) extremely well to camouflage themselves in a habitat devoid of shelter. When viewed at a 45° angle, which happens to be the most common angle for predators to strike from, open ocean fish reflect polarized light more effectively than a man-made mirror. These types of studies not only help explain how small pelagic fish can avoid predation, but also how marine species utilize their unique visual environment to their advantage.
Enjoy the Podcast!