Do you ever feel like all of the talk about climate change and environmental conservation never really gets us anywhere? Like people push and push for laws and protections for species/habitats but there’s never any improvement? Well, here’s some good news, all of this pushing may have started to work!
In this post we summarize a recent review article by Carlos M. Duarte, a marine ecologist at King Abdullah University of Science and Technology, and colleagues. They take a look at how environmental policies that were implemented years ago, have impacted our global oceans; and how, with new legislation and continued work, the ocean could be restored in just 30 years.
"...when scientifically driven legislation is implemented over a long period of time, we see recovery of marine ecosystems."
The authors list a variety of pressures that have pushed ocean ecosystems to the brink of collapse such as anthropogenic climate change, overfishing, and pollution. They also assess how policies that were implemented in the 1970s and 1980s, e.g. the Convention on International Trade of Endangered Species (CITES, 1975, https://cites.org/), have worked over time. Many of these efforts have been forgotten or are taken for granted, but as demonstrated in the review, they have had a profoundly positive impact on ocean ecosystems. For example, the number of species listed as ‘threatened’ on the IUCN (International Union for Conservation of Nature) decreased significantly between 2000 - 2019, and the number of humpback whales has risen from hundreds to 40,000 since they were listed as a protected species in 1968. Unfortunately, due to incomplete datasets, it is difficult to assess how well we have managed some pressures like overfishing. The fragmented data we do have show that fishery policies implemented at regional levels have positively impacted fish stocks. The authors also analyzed how the establishment of Marine Protected Areas (MPAs) had influenced the recovery of vital habitats like seagrass beds, mangrove forests, and coral reefs. The message from this section of the review is clear, when scientifically driven legislation is implemented over a long period of time, we see recovery of marine ecosystems.
Pretty Light Marine Protected Areas
Want to explore an MPA? This virtual scuba dive is a great way to explore an incredibly diverse ecosystem while in lock down.
If you want more, Google Earth has also uploaded multiple virtual dives, check them out here: Google Oceans.
The authors make a point of stating that there’s no use in trying to ‘restore’ the ocean to one specific point in time because our understanding of the global ocean is extremely limited and many changes (e.g. extinct species) can’t be reversed. So what can we do? According to Dr. Durate, focusing on the restoration of important organisms (called keystone species) as well as habitat restoration is a good start. By protecting and restoring these key factors of the marine ecosystem, the world would benefit both, ecologically and economically.
This review article also described ‘a roadmap to recovery’ which provides a detailed outline of what steps need to be taken in order to restore the ocean. First, the authors call for patience. The time it will take for ecosystems and species populations to recover is variable, anywhere from a few years to decades.
Estimated Recovery Time of Various Marine Life
The figure is built using data from Table S3. Reported ranges of recovery times for different groups of organisms and habitats. Durate et al., 2020.
Second, they point out the need for an increase in the number of MPAs and the reduction in pollution (plastics, oil spills, carbon dioxide, etc). Along with the roadmap to recovery, obvious roadblocks are listed in this article such as an increasing human population which puts a greater strain on natural resources as well as a variety of pressures exerted on the ocean by man made climate change. To overcome these obstacles, there need to be incentives put in place that would motivate companies to stop developing intertidal zones as well as encourage current landholders to protect these fragile and unique systems. Also, we must reduce the amount of carbon released into the atmosphere, which may prove to be the most difficult roadblock to overcome, as it requires international cooperation and major changes to the current economic and political situation.
All of these efforts will require large economic investments before any positive results will be seen. However, a healthy ocean can provide a large boost to the economy. The authors provide an estimate of the economic return on these investments and its considerable, $10 return for each $1 that is put into restoration projects. These estimates are a key point when convincing governments and other stakeholders that the ocean is worth restoring. Restoration and protection of fisheries, intertidal areas, and other marine habitats would provide jobs (commercial/local fishing and ecotourism) as well as protection from natural disasters (wetlands lessen the blow of hurricane storm surges and related flooding).
Overall this review provides a well organized outline of 1) what has already been done to restore/protect the global ocean; 2) what policies are working/how well they are working; 3) what we can do in the future to continue fixing the damage that’s already been done; and 4) the benefits that these actions would provide.
Glossary
Marine Ecosystem - a community of organisms (animals, microbes, plants) that interact with/depend on each other.
Marine Protected Areas (MPAs) - an area of the ocean that is under ‘protection’ that can be managed by any level of government. According to NOAA, “MPAs may be established to protect ecosystems, preserve cultural resources such as shipwrecks and archaeological sites, or sustain fisheries production”.
Intertidal zones - NOAA defines intertidal zones as, “anywhere the ocean meets the land, from steep, rocky ledges to long, sloping sandy beaches and mudflats that can extend for hundreds of meters”.
Works Cited
Duarte, C.M., Agusti, S., Barbier, E. et al. Rebuilding marine life. Nature 580, 39–51 (2020). https://doi.org/10.1038/s41586-020-2146-7
NOAA website - Marine Protected Areas. https://oceanservice.noaa.gov/facts/mpa.html Accessed April 13, 2020.
NOAA website - Intertidal Zones. What is the intertidal zone?. Accessed April 13, 2020.
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