Hurricanes, El Niño and harmful algal blooms in two sub-tropical Florida estuaries: Direct and indirect impacts

Abstract

future increases in the intensity of hurricanes and el niño periods predicted by climate change models have focused attention on their role in stimulating harmful algal blooms (HABs). A series of hurricanes that recently impacted florida (USA) provided a unique opportunity to explore the relationships between hurricanes, el niño and HABs in two florida estuaries subject to repeated intense ecosystem disruptive HABs, the indian River Lagoon and the St. Lucie estuary. the roles that hurricanes and el niño play in contributing to HAB events are examined in the context of key structural and functional features of each estuary and their watersheds, including morphology, water residence time and hydrology, such as the influence of Lake Okeechobee discharges into the St. Lucie Estuary. The most direct impact was the increase in rainfall associated with hurricanes and el niño, resulting in enhanced nutrient loads which drive HABs in the indian River Lagoon and Lake okeechobee. Major HABs in Lake okeechobee also present an indirect threat of freshwater HAB blooms in the St. Lucie estuary via mandated discharges from the lake into the estuary during high rainfall periods. conversely, during the absence of HABs in Lake okeechobee, short water residence times produced by discharges into the St. Lucie estuary can result in lower bloom intensities.

Polystyrene microplastic contamination versus microplankton abundances in two lagoons of the Florida Keys

“…Similar observations have been made for microplastics in other ecosystems 59 . Analogous observations have been made for microplanktonic algae abundances in coastal marine ecosystems with long residence times 25,30,60,61 .…”

Environmental drivers of habitat use by common bottlenose dolphins (Tursiops truncatus) in the Indian River Lagoon, Florida, USA

“…The loss of natural hydrologic buffers (e.g., loss of wetlands and natural drainage features and their flood storage and flow attenuation capacities), and leaking septic tanks and substantial increase of drainage area via drainage canal connection to Lake Okeechobee (Lapointe et al, 2020), compromises the St. Lucie Estuary's and southern IRL's ability to rapidly recover from hurricanes (Steward et al, 2006). Freshwater discharges into the St. Lucie estuary in the wet season of 2005 reduced salinity to near 0‰ in areas that often range between 10‰ and 25‰, and HABs periodically occurred throughout the following year, affecting DO (Phlips et al, 2020). Future work should incorporate fine scale studies targeting significant disturbance events to assess their effects on movement and variation in ranging patterns of resident animals.…”

Impact of Climate Change on International Health Security: An Intersection of Complexity, Interdependence, and Urgency

“…Last, but not least, the gradual acidification of the oceans is beginning to affect the overall aquaculture and food chain sustainability, especially across the densely populated coastal areas that heavily rely on fish and other forms of seafood for ongoing food security [154][155][156]. Associated phenomena include harmful algal blooms which further damage aquatic ecosystems [157].…”