Human impact has had a significant influence. The earliest documentation of the estuary being altered was 2000 years ago when the indigenous people built a canal. In the 1860s, the first documented settlers started to arrive and the completion of US-41 in 1926 advanced urban development. In 1930, dredge and fill started and the loss of mangrove lined shores, seagrass beds and oyster habitat became apparent.
Drainage from the altered surrounding landscape has caused for severely altered salinity. It also has created a mixing and circulation pattern from runoff, which has negatively impacted the health of the estuarine system.
Assessing the past and present benthic habitat and the mangrove shoreline was accomplished by assessing aerial images, and systematically sampling the bottom. Aerial images along with interviews of long-time residents were used in determining the distribution of benthic and vegetative.
GIS was used to analyze changes in the seagrass and oyster habitats. It was determined that seagrass and oyster habitat was reduced 80-90% due to dredging activity. The development of waterfront properties removed 70% mangroves and 53% of the bay’s perimeter has increased 23% due to construction of canal systems.
Mapping of the area’s habitat identified large-scale spatial changes that have occurred in Naples Bay, temporal response to the estuarine system to chemical and hydrological stressors. Sediment cores were collected and sampled from 4 sites within the Naples Bay and a fifth from a relatively undisturbed site.
Radioisotopes analysis was used to determine sediment chronology and accumulation rates at each of the sites. Sedimentation rates remained relatively constant over the past 100 years. There were noted disturbances in 1920s and 1950s, corresponding to hurricane and channelization respectively.
Further chemical and sedimentary analyses will help to add confidence to these interpretations and will add to our understanding of the history of this anthropogenically-altered system.