When an area of ocean or coastline is changed or degraded beyond the point that it can serve as a home for the species that live there, or is even destroyed entirely, that’s habitat loss.
There are various ways that the habitats are altered or destroyed. Again, some are direct, like cutting down mangroves or trawling fishing nets over reefs, and others are indirect, such as pollution, which might affect water quality to the extent that the water becomes uninhabitable. Coastal development has accelerated over time as the human population grows and more and more people move to the coast, and it has been the driver of a lot of degradation in marine areas. Mining and aquaculture are other culprits.
The areas that are most accessible to people are the ones most degraded, so broadly in descending order the most affected are terrestrial areas, freshwater habitats, estuaries, coastal areas, the inshore region and the open ocean. This means that fish that live in fresh or brackish waters are likely to be the most affected by habitat degradation.
Many fish species use coastal and estuarine areas as safe places away from predators to feed, give birth, mate and grow. Fish that live in coastal areas for all or part of their lives are likely to be more affected by habitat loss than those that live in the open ocean. Coral reefs and mangroves are also important for various fish species, and both of these habitats have been in decline in terms of their extent and health with rising sea temperatures, coral bleaching and increasing sea acidification.
Through research projects, such as those supported by the Save Our Seas Foundation, we can understand the effects of habitat loss.
What activities have the greatest and the least impact? Which species face the biggest threat from habitat loss? Where are species affected (or unaffected) by habitat loss? The answers to these questions can guide the people who manage ocean resources, marine environments and the activities that impact on marine habitats.
