I would emphasize the need to maintain the saltgrass marsh between the small coastal city and the ocean. In the face of rising sea levels, saltgrass ecosystems may crucially help with sediment accretion and stabilization which is useful for controlling erosion from increasingly large waves (Nordlund et al. 2016). However, the sediment forming the barriers of the marshes could also be destroyed by the power of the waves. At the same time, mangroves are accustomed to being flooded and can adapt to low oxygen levels. However, they would still be impacted by the change in hydrology due to rising sea levels and are also vulnerable to drowning. So, I would mention in the report the importance of taking measures to maintain the marsh and mangrove so they can provide their benefits and not be destroyed.
Also, the saltgrass in the marsh would maintain nursery habitats and bring other benefits (Nordlund et al. 2016). A more detailed distribution of the ecosystem services, dependent on bioregion, provided by saltgrass is shown below (Nordlund et al. 2016). Not all saltgrass genera are equal with regard to the ecosystem services they provide (Nordlund et al. 2016). Larger sized saltgrass genera, for example Posidonia Enhalus, are perceived to provide more substantial and a wider variety of ecosystem services than smaller species, for example Halophila, Lepilaena (Nordlund et al. 2016). That said, the report I create would include investigation into the type of saltgrass at the specific location.
I would also note the benefits of tourism to the small coastal city. Viana et al. (2017) provides a stellar economic model that tracks tourism and fisheries revenues through time for different management options and location characteristics. Accounting for economic benefits will motivate the readers of the report to mitigate the impacts of the rising sea levels (Viana et al. 2017). Findings from the economic model reveal marine reserves are part of the optimal economic solution even in situations with optimal fisheries management and low tourism value relative to fisheries (Viana et al. 2017). For example, in the Great Barrier Reef annual revenue from tourism is 36 times greater than income from commercial fishing (Viana et al. 2017). In the Medes Islands Marine Reserve (Spain) annual revenue from tourism is about 20 times greater than fishing revenue (Viana et al. 2017). Still, the scientists demonstrate how tradeoffs between the two services depend on location attributes and management of the fishery outside marine reserve borders (Viana et al. 2017).
Marine mammals are crucial to maintain the biodiversity of the wetlands and provide interesting sight-seeing that would bring tourism to the small coastal city. Further, I would highlight the need for the city council to recognize the benefit marine mammals provide to reducing excess nitrogen levels. It is well known that microbes, zooplankton, and fish are important sources of recycled nitrogen in coastal waters, yet marine mammals are important in this cycle, as well (Roman and McCarthy 2010). Marine mammals concentrate nitrogen near the surface through the release of flocculent fecal plumes (Roman and McCarthy 2010). Excretion for marine mammals, tethered to the surface for respiration, is expected to be shallower in the water column than where they feed (Roman and McCarthy 2010).
Nordlund, Lina Mtwana, Evamaria W. Koch, Edward B. Barbier, and Joel C. Creed. 2016. “Seagrass Ecosystem Services and Their Variability across Genera and Geographical Regions.” PLOS ONE 11: e0163091. doi: 10.1731/journal.pone.0163091.
Roman, Joe and James McCarthy. 2010. “The Whale Pump: Marine Mammals Enhance Primary Productivity in a Coastal Basin.” PLOS ONE 5: e13255. doi:10.1731/jopurnal.pone.0013255.
Viana, Daniel F., Benjamin S. Halpern, and Steven D. Gaines. 2017. “Accounting for tourism benefits in marine reserve design.” PLOS ONE 12: e0190187. doi: 10.1731/journal.pone.0190187.
Response by Professor Fenton Kay:
Great stuff, Mary. Look at my question to Amanda above. What would you recommend to Ciudad Matamoros to provide them with protection against sea-level rise?
Considering Ciudad Matamoros faced Hurricane Hanna in July 2020, it is interesting to look into your question.
I would recommend policymakers designate wetlands in flood and storm prone zones as protected areas (The Ramsar Convention 2016). I would also recommend they restore degraded wetlands as they could act as protective barriers (The Ramsar Convention 2016). Coastal wetlands in the United States helped avoid more than $625 million in damages from Hurricane Sandy in 2012 (The Ramsar Convention 2016).
Also, I would recommend installing revetments at the shoreline. Revetments of broken concrete or riprap are powerful devices for reducing the energy from wave action, and they are repaired inexpensively. Their irregular surface offers protection from wave run-up, or the movement of breaking waves up the shore.
The Ramsar Convention. 2016. “Wetlands: a natural safeguard against disasters”. https://www.ramsar.org/sites/default/files/fs_9_drr_eng_22fev.pdf
Original Post by Michael Muehlberger:
One of the areas that I would focus my investigation on would be the mangrove forest. Mangroves are essential in “[protecting] shorelines from damaging storm and hurricane winds, waves, and floods” (Florida Museum, 2020). They’re also able to slow tidal motion, which in theory would help prevent extreme damage from storm surges (National Ocean Service, n.d.). With the sea level rising flooding will become a more prominent and frequent concern for coastal communities, and any assistance they can get in minimizing the impact is crucial. Mangroves also help prevent erosion of the coastline by stabilizing sediment with their entangled roots (Florida Museum, 2020). Sea level rise will naturally cause coastal erosion (which can cause damage through the loss of land), and other methods used to prevent this erosion can become costly (US Climate Resilience Toolkit, 2019). Protecting the mangrove forest will allow for a natural barrier against erosion, and hopefully have less of a financial impact.
On top of these benefits mangrove forests are also home to many unique vertebrates and invertebrates, including some Threatened and Endangered species (Florida Museum, 2020). A few of these species are highly charismatic (e.g. West Indian manatee, green sea turtle, American alligator) and many people rely on the mangrove forests to provide ecotourism opportunities to see these species. In conducting the investigation for the report, I would want to focus on how sea level rise would impact these species, and if the mangrove forest would provide any protections for them aside from the normal protections. If flooding were to increase as a result of the rising sea levels then it’s possible these species might be able to access previously unavailable locations, and that would definitely cause a problem.
I would want the council to understand all the pros that a mangrove forest provides, and I would advocate for protections to keep these mangroves from disappearing. The mangroves will protect the community from the various problems sea level rise may cause, and the benefits from the ecotourism opportunities would help bring a financial gain to the area. Obviously the saltgrass marsh and the estuary would need to be investigated too since they all play a role in protecting against sea level rise. However, I personally feel like the mangrove forest might be the best place to start the investigation.
Florida Museum. 2020. “South Florida Aquatic Environments: Importance of Mangroves.” Accessed November 10, 2020. https://www.floridamuseum.ufl.edu/southflorida/habitats/mangroves/importance-mangroves/#:~:text=Mangroves%20protect%20shorelines%20from%20damaging,trapping%20sediments%20originating%20from%20landLinks to an external site…
National Ocean Service. n.d. “What is a ‘mangrove’ forest.” Accessed November 10, 2020. https://oceanservice.noaa.gov/facts/mangroves.htmlLinks to an external site..
U.S. Climate Resilience Toolkit. 2019. “Coastal Erosion.” Accessed November 10, 2020. https://toolkit.climate.gov/topics/coastal-flood-risk/coastal-erosion#:~:text=Already%2C%20coastal%20erosion%20costs%20roughly,structures%20and%20loss%20of%20land.&text=Coastal%20erosion%20is%20the%20process,or%20sands%20along%20the%20coast
Stellar post highlighting the importance of mangroves to a small coastal city. I found a video showing how mangrove roots provide a nursery for fish in Mexico. It explained how there are certain fish that only live inside mangroves. It goes on to say these fish can be a major component of the supply for fish markets in a city. The video also mentioned the mangroves filter water for the people of the city. That said, in the last 50 years, our planet has lost half of its mangroves and the researcher used drones to estimate the amount of mangrove cover that still remains. Drones are used to estimate the area and volume of the mangrove forests as well as the quantity and type of animals living there. With that information, scientists can create conservation priorities to protect biodiversity. Check it out!:
The next video describes the benefits of mangroves and a strategy to protect them through a case study in Gazi Bay, Kenya (its forest stores 1,500 tons of carbon/hectare):