A Summary of Boris Worm’s “Impacts of Biodiversity Loss on Ocean Ecosystem Services

The impact of marine ecosystems influenced by human nature has been severely crippled over the past years. Loss of species and their populations are visible evidence that this is occurring, yet there are plenty of unknown consequences as well. What Boris Worm set out to do was see how biodiversity is affected from the long-term practice of global fisheries: they found that “resource collapse increased and recovery potential, stability, and water quality decreased exponentially with declining diversity.” On the other hand, restoring biodiversity seemed to increase productivity; therefore, Worm’s conclusion is that the loss of biodiversity in marine ecosystems is exacerbating the inability of the ocean to provide food, quality water, and recovery from ecological disasters. However, these trends can still prevented.

Research done on land animals tend to suggest the same thing: a richer biodiversity enhances the productivity and stability of ecosystems. The vast expanse of oceans makes it particularly difficult to forecast the scope of our impact on marine ecosystems. Because many people are dependent on water systems as a means of survival, changing the landscape can have deleterious effects on these communities. These effects stem from the practice of “exploitation, pollution, and habitat destruction, or indirectly through climate change and related perturbations of ocean biogeochemistry.” The loss of coral reefs, estuaries and ocean fish communities are a result of these practices.

Biodiversity enhances ecosystems in many ways: they provide stability, resistance to disturbances in habitats, and provide mixed diets to species that prolong survival such as growth and fecundity. The research on biodiversity reports “positive linkages between biodiversity, productivity, and stability across trophic levels in marine ecosystems.”

For coastal ecosystems, a decline of species strongly correlated with the onset of industrialization, and as predicted, ecosystems were able to survive with an increased richness in species and was conclusively more stable. When coastal ecosystems are unable to filter water and increase water quality, there were increases in pollution, algal blooms, and oxygen depletion; as a result, the survival of native species (and at times compromised by invasive ones) were declining.

In large marine ecosystems, the rate of global fisheries have collapsed by 29% since 2003 defined by the recorded maximum. As with current trends from the research above, collapses occurred more frequently in areas which were not rich in biodiversity. In areas where species richness was abundant, these ecosystems tend to be more robust and less susceptible to overexploitation.

The issue is whether these trends can be reversed. The implementation of reserves and closures have been used on regional and local scales. The question is whether it can be replicated on a larger scale. Reserves and closures have reversed some aspects of declining biodiversity and were associated with “large increases in fisheries productivity.” Ecosystems tend to stabilize although not significantly in many cases. Results vary from place to place, but some of the data suggests that it is still possible to recoup some losses in biodiversity from these areas. This trend towards a less biodiverse world has many implications: Worm’s findings demonstrate that “the elimination of local adapted populations and species not only impairs the ability of marine ecosystems to feed a growing human population but also sabotages their stability and recovery potential in a rapidly changing marine environment.” Our efforts must prove prudent if we are to live in a sustainable world, and that begins by rethinking the life of marine ecosystems.

What can we do to prevent a catastrophic decline in ocean fisheries by the mid-21^st century?

In order to prevent a catastrophic decline of ocean fisheries, we must act now. Part of this action includes restoring the biodiversity in our oceans through sustainable practices in fisheries management. We must also be able to control the level of pollutants entering our ecosystems, and maintain the marine habitats necessary for life. The creation of marine reserves can also help curb and prevent a decline in ocean fisheries. If we are successful in our ventures in being sustainable when it comes to marine ecosystems, we might be able to address growing concerns of food security and water quality for habitats conducive to the proliferation of life.

Worm, Boris. “Impacts of Biodiversity Loss on Ocean Ecosystem Services.” Sources: Selection in

                Environmental Studies. Ed. Thomas Easton. United States, 2014. 92-95.