Link:Dr. James Douglass Marine Ecologist Personal Blog/CERF Report 2019

From Indian River Lagoon Project
This is an excerpt from Dr. Douglass' Personal Blog dated 11 November 2019.

About CERF 2019

I just got back from five days at the 2019 Coastal and Estuarine Research Federation (CERF) conference in Mobile, Alabama.

My early-career research addressed a lot of basic issues like how grazers and predators, and biodiversity, per se, affect ecosystem processes. I’m still interested in those general topics, but my research since joining the faculty at Florida Gulf Coast University has been more “applied,” addressing particular environmental problems affecting seagrass beds and water quality in Southwest Florida. Going to this CERF conference, and schmoozing with other practitioners of both basic and applied research, was very helpful in inspiring me and giving me useful research ideas. I’ll briefly review some memorable things I picked up from the conference.

Living Shorelines

Living shorelines” are a growing, green revolution, even though most people don’t know what they are. Sea level rise, subsidence, and erosion are eating away at the coasts of the world, threatening both natural habitats and man-made coastal developments. The old way of dealing with this was by heavy-handed “coastal armoring” (seawalls, jetties, dikes, etc.), which tended to be expensive, bad for the environment, and prone to failure. The living shorelines approach uses natural protective elements like oyster reefs, mangroves, and saltmarsh grasses, in combination with man-made structural elements, to protect coasts in more natural, self-sustaining, and environmentally-beneficial ways. I saw talks showing how various living shoreline projects had reversed erosion, helped absorb nutrient pollution and carbon dioxide pollution, and created naturally-expanding habitats for birds, fish, and shellfish. Southwest Florida has hundreds of kilometers of eroding or unnaturally-armored canals and coasts that are prime candidates for living shoreline projects.

Seagrass Decline

The global trend of seagrass decline from the mid 20th century until now may have finally hit bottom and turned around into a recovery phase. However, this optimistic forecast is driven by a few, positive cases of recovery. Seagrasses continue to decline in many areas. Water quality seems to be a key factor differentiating the happy seagrass stories from the tragedies. Where water quality is naturally good, and/or there have been concerted efforts to improve water quality, seagrasses have spread and algae blooms have decreased. However, where pollution oversight has been lax, repeated harmful algal blooms and other water quality issues have devastated seagrass beds. Below is a rank of several important seagrass ecosystems in the eastern United States from most exciting recovery to most tragic decline in recent decades.

Indian River Lagoon Paradise Lost

There’s one major seagrass system in Florida that is doing even worse than SW Florida, and that is the Indian River Lagoon (IRL)- a long, narrow estuary that runs parallel to the coast from Palm Beach to Cape Canaveral. The IRL is significant as the most biologically diverse estuary in the United States, because it spans from the temperate zone to the tropics and has a blend of species from both zones. A lot of those species depend directly or indirectly on the seven species of seagrasses found in the IRL. Up until 2011 the seagrasses and water clarity were slowly declining as a result of nutrient loading from human population growth in the areas around the IRL, combined with water quantity and salinity problems related to various canal systems and water diversions. But in 2011 the sh*t really hit the fan with a so-called “superbloom” of phytoplankton. The plankton darkened the waters and wiped out a majority of the IRL’s seagrass beds. Since then there have been all kinds of other nasty phytoplankton blooms alternating with nasty seaweed blooms, fish kills related to low oxygen, and even a super duper bloom in 2016 that was bigger than the original super bloom. It’s going to take a lot of nutrient reduction work, including septic to sewer conversions, new regulations on agriculture and suburban fertilizer use, wetland restoration, and other projects to restore the IRL. Needless to say, stricter limits on growth and sprawl are also desperately needed in the IRL watershed, as they are in SW Florida’s watersheds. PS- Another Florida East Coast estuary that I’ll lump in with the IRL is Biscayne Bay, the high salinity estuary off of South Miami. It recently lost almost all its seagrasses as the culmination of decades of chronic nutrient loading and declining water quality. To preserve delicate ecosystems like seagrasses and reefs next door to a heavily populated area takes a serious investment in nutrient reduction infrastructure and regulation. Boston and Tampa did it fairly well, but SW Florida and SE Florida have dragged their feet to dire effect.

Climate Change

Climate change effects are showing up all over the place. A lot of research was presented on climate change impacts such as warming, sea level rise, and species range shifts. One of the sea level rise impacts examined was the shift of coastal forests to saltmarshes as saline water inundates roots. There were also tons of studies of the expansion of the black mangrove (Avicennia germinans) northward into former saltmarsh habitats. If the trend continues mangroves will eventually replace most of the saltmarshes along the Gulf of Mexico coastline. Seagrasses are also undergoing species range shifts. For example, in North Carolina where the temperate seagrass Zostera marina is at the southern end of its range and the tropical seagrass Halodule wrightii is at the northern end of its range, the ratio of the two coexisting species is shifting in favor of the tropical one. My own research colleagues presented data from turtlegrass (Thalassia testudinum) beds from Panama to Bermuda, which suggested that the intensity of grazing by tropical grazers is increasing in some areas,
Indian River Lagoon Encyclopedia Article - Dr. James Douglass Marine Ecologist Personal Blog/CERF Report 2019