It is no secret that we humans get a lot of our food from the ocean, which at times can be very irresponsible. Certain species of fish has already seen a big decline in population numbers, and we will most likely have to face the fact that many species of fish will go extinct in the next few decades. It can be very difficult to regulate fishing, and in this post I am going to take a bit closer look at how small no-fishing zones next to breeding grounds for penguins has affected their survival rate.
African penguins. Image by Wikimedia Commons users Charlesjsharp, posted with the Creative Commons Attribution-Share Alike 3.0 Unported license.
The African penguin got no-fishing zones around their breeding islands
The African penguin (Spheniscus demersus) is found on the southern coast of Africa, where it used to be very common. However, like a lot of other species the African penguin has faced many threats in the last decades, resulting in a big population decline. At this point they are considered Endangered by the IUCN, so there is cause for some concern.
87 % of the South African population is centered around just 8 different breeding colonies, each with their own island. There are about 19,300 breeding pairs in the country, as well as just over 5,700 in Namibia, leaving it at just about 25,000 breeding pairs in total. This is not really a lot for an entire species of penguins, and as mentioned above, they are currently facing a sharp decline in population numbers.
One thing that was done in order to try to help the African penguin thrive and rise in numbers again was to create small no-fishing zones in the areas around their breeding islands. The only problem was that no one really knew if this would even help, since the fish could easily just swim out of these small no-fishing zones. Yet they were tested out, and some of the breeding islands got a 20km sanctuary around them, so no fishing vessels were allowed to harvest forage fish within 20 kilometers of the islands.
20km might sound like a lot, but it’s not really that much for fish that are swimming constantly. Note that the ban was only on forage fish such as sardines and anchovies, which are key species for the endangered African penguin. These fish also serve a very important ecological function by eating small marine invertebrates and even plankton, and serves as a middle-man between piscivorous animals and these small organisms.
The amount of forage fish that are caught by fishermen seem to be rising each and every year, and some scientists believe this could have a big ecological consequence if we keep increasing this number. However, other believe that this is not really a problem, so there is a lot of debate about this.
The no-fishing zones improved the body condition and survival rate of the chicks
In order to find out if the no-fishing zones even had any effected, the scientists who worked on the experiment had to compare the survival rate and body condition of the chicks before and after the implementation of the sanctuary. What they found out was that it had without a doubt increased both of these factors in the year after the no-fishing zone was implemented, but also make sure to tell us that more data is needed before we can be absolutely sure that this has such a big effect.
Is it applicable to other species and areas?
This is of course the million dollar question. The paper shows that it did indeed increase both the body conditions and the survival rate of the young chicks that hatched in these protected no-fishing zones, but since this has not been tested anywhere else, we can’t say for certain that it is a good strategy for conserving penguins and other species who rely of forage fish to survive.
When making an experiment like this one, there are so many things that can interfere with the experiment, which means that it must be tested in other places during other conditions before we can assume that it’s universally applicable.
Thanks for reading
Thanks for reading, and don’t forget to leave a comment below! If you want to learn more, then check out the paper that was published in Proceedings of the Royal Society B. If you want to learn more about the African penguin, then I suggest the IUCN page that I linked to earlier in the text. They are the one who are responsible for classifying its conservation status, and they have lots of details about the species in their justification for the endangered status it has been given.
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