As any reader of this blog will know, most of the research in the Bowman Lab is focused on polar microbial ecology. Although focusing a research program on a set of geographically-linked environments does have advantages, primarily the ability to spend more time thinking in depth about them, there is I think something lost with this approach. Insights are often gained by bringing a fresh perspective to a new study area, or applying lessons learned in such an area to places that one has studied for years. With this in mind lab member Natalia Erazo and I are launching a new field effort in coastal Ecuador. Natalia is an Ecuadorean native, and gets credit for developing the idea and sorting out the considerable logistics for this initial effort. Our first trip is very much a scouting effort, but will carry out some sampling in the Cayapas-Mataje Ecological Reserve and near the town of Muisne. Depending on funding we hope to return during the rainy season in January-February for a more intensive effort.
Our primary objective is to understand the role of mangrove forests in coastal biogeochemical cycling. Mangroves are salt-tolerant trees that grow in tropical and sub-tropical coastal areas around the world. They are known to provide a range of positive ecosystem functions; serving as fish habitat, stabilizing shorelines, and providing carbon and nutrient subsidies to the coastal marine environment. Globally mangroves are under threat. The population density of many tropical coastal areas is increasing, and that inevitably leads to land-use changes (such as deforestation) and a loss of economic services – the social and economic benefits of an ecosystem – as economic activity ramps up. The trick to long-term sustainability is to maintain ecosystem services during economic development, allowing standards of living to increase in the short term without a long-term economic loss resulting from ecological failure (such as the collapse of a fishery or catastrophic coastal flooding). This is not easily done, and requires a much better understanding of what functions exactly, specific at-risk components of an ecosystem provide than we often have.
One particular land-use threat to the mangrove ecosystem is shrimp aquaculture. Mangrove forests in Ecuador and in other parts of the world have been deforested on a massive scale to make room for shrimp aquaculture ponds. In addition to scaling back any ecosystem functions provided by the mangrove forest, the shrimp aquaculture facilities are a source of nutrients in the form of excrement and excess feed. On this trip we will try to locate estuaries more and less perturbed by aquaculture. By comparing nutrient and carbon concentrations, sediment load, and microbial community structure between these areas, we will gain a preliminary understanding of what happens to the coastal ecosystem when mangroves are removed and aquaculture facilities are installed in their place.
Our first stop on this search will be San Lorenzo, a small city in the Cayapas-Mataje Ecological Reserve near the border with Columbia. I’m extremely excited to visit the Reserve, which has the distinction of hosting the tallest mangrove trees anywhere on Earth. We may some meager internet access in San Lorenzo, so I’ll try to update this blog as I’m able. Because of the remote nature of some of our proposed field sites we’ll have a Garmin InReach satellite messenger with us. We plan to leave the device on during our field outings, you can track our location in real time on the map below! The Garmin map interface is a bit cludgey; you should ignore the other Scripps Institution of Oceanography users listed on the side panel as I can’t seem to make them disappear.