 Protecting our planet: the importance of
decapod crustaceans
You’ll probably have seen multiple news stories and social media posts covering conservation efforts for iconic animals; think tigers, sharks, elephants, and sea turtles. However, you’ll rarely see the same attention put on invertebrates, even though they make up around 95% of all animal species on earth!
Invertebrates play a critical role in the health of our planet – the world would literally collapse without them.
We might all know that invertebrate animals like bees are crucial pollinators, or that termites are essential for breaking down dead wood and other organic materials. Their work impacts the lives of species around the world, including humans.
But it’s perhaps less widely known that decapod crustaceans are just as important because they greatly influence the world around them in similar ways.
From recycling nutrients and protecting coral reefs to supporting global food webs and regulating climate processes, these invertebrates are essential to life on Earth. Understanding the ecological importance of crustaceans highlights why their conservation matters for both ocean health and human survival.
The ecological role of decapods – why should you care?
When we are sat in our homes or doing our weekly food shop, it can be difficult to see how crabs, lobsters, and shrimp could affect our lives so significantly. Their roles are often invisible, but in the background, they are shaping our landscape, recycling nutrients, and supporting the biodiversity of our planet. They are the unsung heroes we should be celebrating, not ignoring.
Nature’s architects and ecosystem engineers
“Nothing is art if it does not come from nature.”
When crustaceans go about their business, they are constantly altering the environment. This paves the way for the creation of new habitats and influences the flow of nutrients, which in turn improves the health of the surrounding area. For example, mud crabs dig complex burrows for themselves in mangroves, which creates microhabitats for other species like marine worms and mud shrimp. The movements and burrowing activities of crustaceans also spread organic debris, oxygenate plant roots, and create new seeding areas. This can have surprisingly far-reaching consequences, providing food for a variety of other species, many of which we fish for, and increasing much-needed oxygen levels and vital nutrients in the ocean.
What does this mean for humans?
Ocean nutrient cycling in the ocean, partly fuelled by the movements of crustaceans, generates oxygen and regulates our climate. We’ve already witnessed the extreme weather conditions that come with climate change, from abnormal heatwaves to intense wildfires. This would only get worse if crustaceans went extinct. Over 3 billion people also rely on the ocean for their livelihoods. With less nutrients being dispersed, this would likely affect the diversity of fish and plants that we rely on for food and money.
Waste disposal and coral reef protection
“Waste is a resource in the wrong place.”
Many decapod crustacean species are scavengers, feeding on everything from algae and leaf litter to dead animals. Their smart digestive systems effectively recycle nutrients from the food they eat, which are then released back into the ocean. Without crustaceans, the ocean would become a wasteland of suffocating, murky water and piles of decaying matter.
Decapod crustaceans are particularly useful in the maintenance of coral reefs. Considering that more than 70% of the world’s coral reefs are threatened with extinction, this is a very special superpower that needs to be protected. For example, coral guard crabs live within the branches of coral colonies, scraping sediment, algae and mucus from the surface, which keeps it clean and healthy. They will also readily attack various predators that threaten the survival of their host coral, including snails and crown-of-thorns sea stars (Acanthaster planci).
What does this mean for humans?
There’s a reason that seaside resorts are so popular with people around the world. The scenery is stunning. Can you imagine a world where the sea is a toxic brown mush of waste with discarded fishing nets and crisp packets floating on the surface? Didn’t think so. On top of this, coral reefs offer a surprising number of benefits to humans directly. For example, they act as barriers to protect coastal villages and towns from storms. They are also vital commodities for fisheries and tourism operators. Coral reefs are even sources for new medicines, with potential treatments for cancer and arthritis already being studied. Without crustaceans removing waste from corals, we would lose a lot more than we already have...
Crustaceans as food web contributors
“It’s all about who’s where on the food chain.”
Most of the larger crustacean species have very few predators once they reach adulthood. Yet they can be very vulnerable to predation in their earlier life stages. During the planktonic stage (larva), crustaceans act as vital food sources for a wide variety of other animals, right up to apex ocean predators like whales. Once they become adults, many crab species prey on smaller animals, keeping the whole ecosystem running as it should.
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For example, blue crabs (Callinectes sapidus) are a keystone species, meaning they have a significant influence on their environment. Blue crab larvae serve as food for filter feeders, such as oysters, and juveniles act as vital food sources for birds, fish and even other blue crabs. As adults, they have a varied diet that includes clams, mussels, small crustaceans, decaying matter and practically anything else they can find!
What does this mean for humans?
Crustaceans play a crucial role in the food chain as both predators and prey. They support the entire marine food web on which we heavily depend. If we lose all crustaceans, entire ecosystems will collapse. Don’t forget that crustaceans themselves are also a popular food source for humans around the world, providing us with high-quality protein, omega-3 and vital minerals that improve heart health and support our immune systems. In fact, over 3 billion people rely on wild-caught and farmed seafood, including crustaceans, as a significant food source.
captured by trawling nets.  
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Why protect decapod crustaceans?
“The things that make us different – those are our superpowers.”
While decapod crustaceans greatly benefit the environment, one of the main reasons you should care about their welfare is that they are amazing creatures! From their complex learning capabilities to their impressive ability to regrow limbs, decapods are simply fascinating. They deserve the right to live, thrive, and be cared for, just like any other species.
While decapod crustaceans greatly benefit the environment, one of the main reasons you should care about their welfare is that they are amazing creatures! From their complex learning capabilities to their impressive ability to regrow limbs, decapods are simply fascinating. They deserve the right to live just like any other species.
More and more, we are learning that we need to live in harmony with the environment, rather than against it, not only for the health of the natural world but also for our own benefit. Invertebrates, including crustaceans, contribute to the air we breathe, the materials we use in daily life and the water that sustains us. We believe they deserve more protection.
So, the next time you spot a crab on the beach, just take a moment to think about its life, how these creatures have been maintaining our planet for thousands of years and the superpowers they possess that support us.
Fun Facts
Claw crush: One of the most recognisable features of decapod crustaceans is their claw-like appendages, which can pack quite a punch. For example, the coconut crab can generate a force almost 90 times its own bodyweight!
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Crustaceans face threats in the wild, and we must do what we can to protect them.