And another post inspired by the amazing blue planet 2..
Apart from the amazing footage of the octopus using shells to hide from the shark (pretty impressive, uh?) , this week episode was mostly about the green forests..
Kelp and large seaweeds are very important habitat components, but being 'living habitats' are exposed and at risk the same threats which affect all the rest of marine life: climate change, pollution... you name it! Which means in some cases active protection measures and sometimes restoration are needed to retain these very important features...
Moreover, the presence of these living habitats can change species assemblages, and those changes can reflect back on the forest via feedback loops. Let me explain: if we lose some kelp, we may lose some some species of fish and they may be the same fish species that keep other algae from over-growing and occupy the space so that the kelp cannot come back the following year. Just an example. As David Attenborough showed us, the loss of one species can affect the whole of the system. He used the otter-urchin-kelp trophic cascade, a classic example of how losing the top player can change the game. When otters were hunted, and numbers dropped dramatically, then urchin proliferated and kelp was lost due to urchin overgrazing. This is just an example and similar things happen in other systems.
Did you see how those big spider crabs were afraid of the single ray? Do you know that fear in itself can also change trophic cascades?
When we think of top predators we often think about sharks, however their close relatives, skate and rays, are also at the top of the food chain - well before humans come into play, as we fished out skates from many of our oceans..but recent work , which I was lucky enough to be part of, showed that the presence of skate in itself could help maintainance of bivalve reefs by changing crabs behaviour! This means that if we want to restore bivalve reefs, we have to think more widely about the surrounding ecosystem and take a 'holistic' approach. Restoring reefs, or other systems in general, should include all the components,from top predators to microbes, thus a unification of the many disciplines, and collaborations between ecologists, microbiologists, modellers etc should be encouraged in order to see the full picture!
Disclaimer: some posts may contain affiliate links. At no extra costs to you, buying through the link will help me in this blogging journey!