If I were to put you on the spot and ask you to think of an animal, from any part of the world, which would be the first to come mind? Maybe I’m wrong, but there’s a good chance that animal is a mammal, or perhaps a bird. Even if that’s not the case, it’s likely to be one of the so-called flagship species of the animal world. Almost certainly, we are talking about a vertebrate animal. So, did I come close?
You’re probably thinking, “What’s all this about?”. Let me explain. The unfortunate truth is that certain groups of animals, for one reason or another, have not always received the same attention and consideration as others. This has meant that, over the years certain animals, such as invertebrates, have not been researched, studied and understood in quite the same way. Invertebrates are, therefore, not the first animals that come to mind. But, although it may not seem so, invertebrates are of great ecological importance and play a significant role in human society, something that we will try to explain in this article.
The importance of invertebrates
Invertebrates are a remarkably numerous and widely diverse group of animals, from arthropods to molluscs, and can be found in all corners of the planet. However, despite their great ecological, economic and social importance, relatively few taxonomists and scientists have devoted themselves to studying these animals.
It may seem a cliché, but the potential loss of invertebrates from food webs and ecological organisations within an ecosystem would undoubtedly lead to the collapse of the entire environmental system. But why would this happen? Firstly, because they are a vital source of food for many other animals, and at the same time they participate in biological control and pest control, thereby maintaining a balance within ecosystems. It’s also because they are involved in key processes, such as pollination or decomposition, and are considered valuable environmental indicators. They even help to create and maintain soil quality.
Then, if we consider the economic and social areas, it’s worth noting that invertebrates have a high cultural and aesthetic value in many regions of the world, and can also have a significant influence on the development of human activities. Many invertebrate species are used as a source of raw materials (e.g. silk, dyes and honey) and also as a frequent source of food (crustaceans, cephalopods, bivalves, etc.)
Finally, to further understand the importance of invertebrates in everyday life, it’s interesting to note that a wide variety of species have been repeatedly used in valuable medical and genetic studies, many of them related to the fight against cancer; also as research tools, contributing to the advancement of science. Of all these species, we can mention Drosophila melanogaster and Caenorhabditis elegans (the first multicellular organism to have its genome completely sequenced) as two of the major protagonists in this type research.
Main causes of invertebrate extinction
Here’s a brief description of the main, current causes of extinction faced by invertebrates.
Habitat destruction and fragmentation
Some of the causes that threaten the conservation and survival of invertebrates are the same as those directly affecting other classes of animals. This is the case, for example, of habitat loss and destruction, a universal problem which is recognised as the main cause of species extinction worldwide.
The processes of urbanisation and construction, intensive agriculture and coastal destruction can lead to the fragmentation of the natural environment, displacing invertebrates and isolating them in very small areas, which are more vulnerable to change. For this reason, it is common for many terrestrial invertebrates to end up inhabiting mountain ecosystems, which are less affected by human activities.
Over-exploitation is one of the major problems faced by invertebrates, especially with regards to activities that use non-selective harvesting techniques. This is the case of trawling, an excessive exploitation of the marine life with terrible consequences for the ecosystem. Over-fishing is undoubtedly one of the greatest threats to marine invertebrate species.
Pollution is another reason why many invertebrate species are seriously endangered. Agricultural intensification, coupled with the uncontrolled use of fertilisers and pesticides, can lead to considerable problems such as acidification of rivers, deterioration of habitats or reduced diversity in ecosystems.
Today, the effects of climate change on invertebrate species are better documented than a few years ago: a loss of diversity, changes in the distribution of populations, phenological transformations, etc. All of these harmful consequences affect the survival of the most specialised animals.
The introduction of invasive species
The introduction of invasive species is not a recent occurrence, but it’s something that has had a serious impact on the planet’s natural ecosystems over the centuries. Displacement, competition and, ultimately, extinction, are some of the possible consequences for native species sharing the same ecological niche with alien species.
Conservation measures for invertebrates
As we have seen in this article, invertebrates are of extraordinary ecological, economic and social significance, which is more than enough reason to focus a considerable amount of effort and resources on their conservation. But what steps can we take to improve invertebrate conservation projects?
Firstly, it’s important to carry out a range of research that contribute to improving our understanding of species distribution, the evolution of populations and their environmental needs. A rigorous species population census, for example, is key for any conservation actions. It is also necessary to identify, as far as possible, the causes of the decline and regression of each species, and to put together an appropriate management plan for each one.
Also, in ecosystems and habitats a series of measures must also be carried out to increase the number of individuals until optimum population levels are reached. These can include the protection of the most suitable populations and reintroduction of traditional land uses.
Finally, it is no less important to raise awareness among the general public, most of whom are quite unaware of the existence of many of these species and the threats to their survival.
Translated by Carlos Heras