Shore + Sound
Swimming, Clamming & Heavy Rain Plovers and Others
The Water of Long Island Sound Trends Under the (Rising) Surface
Swimming
Coastal swimmers saw fewer beach closings in 2018 than in 2017, but still more than in 2015-16.
The Council adds up the number of days that each coastal city and town closed one or more of its public beaches, and calculates an average for all the coastal cities and towns with beaches. Continue reading about beach closings caused by pollution...
Clamming and Oystering
The area of the Sound unconditionally approved for harvesting shellfish was unchanged in 2018.
The Connecticut Department of Agriculture's Bureau of Aquaculture and Laboratory Services monitors shellfish beds and classifies them according to their potential for yielding healthful, uncontaminated shellfish. The chart immediately above shows the acreage of shellfish beds that are included in the "approved" category for direct harvesting because they are generally unaffected by pollution.**
There is also a "conditionally approved" category, which requires a management plan and might be subject to closings seasonally or after rainfalls. (Even areas that are "approved" may be closed as a precaution following exceptional rainfalls of three or more inches.) Aquaculture experts have suggested that the gradual, historic shrinkage of "approved" shellfish beds is associated with an increasing volume of runoff from lawns and pavement flowing further into the Sound. Shellfish beds can be closed in anticipation of rain events that will wash pollutants into receiving waters. The drought conditions which persisted during 2016 resulted in fewer closures.
The Source of the Goal
The goal for shellfish beds, adopted in the 2015 edition of the Long Island Sound Study's Comprehensive Conservation and Management Plan, is to upgrade five percent of the 2014 restricted acres so that shellfish may be harvested in those areas freely. Adding those upgraded acres results in a target of approximately 139,550 "approved" acres by 2035, shown on the chart as a horizontal line.
Forecast: More Heavy Rains
Connecticut residents have witnessed a steep increase in the amount of rain arriving in downpours. In October 2015, the National Weather Service updated the precipitation frequency data for Connecticut that had last been published in 1961. The new data confirm what had been predicted by many: rainfalls are getting heavier, and heavy rains are becoming more frequent. In 1961, most of the state would have expected a four-inch one-day rainfall every five years or so; in some northwestern towns, that five-year storm would have brought less than four inches. Now, all portions of the state can expect the five-year storm to bring well over four inches and, in some northwestern Connecticut towns, close to five inches.
While this trend, generally attributed to a changing climate, can be found throughout the country, it is particularly strong in the northeastern states. The 2014 National Climate Assessment predicts this trend to strengthen.
Coastal swimmers enjoyed more "open" beach days in 2018 than in 2017, but still had to contend with more days closed than any other year since 2012.
Yearly variations are products of rainfall patterns and unusual incidents such as sewer-line ruptures. Polluted surface runoff and sewage overflows after rainstorms are the most common sources of bacteria. After heavy rains, health officials must assume that polluted runoff and/or overflows from combined sanitary/storm sewers have raised bacteria levels. Though beaches are regularly monitored for bacteria, test results are not immediate. More closings are initiated preemptively, as a precaution after heavy rain, than are initiated due to actual monitoring results. Over fifty percent of beach closures in 2018 were attributed to the impacts from storms and runoff.
The cities and towns on the western half of the state's shoreline usually have a higher frequency of closings. The western half of the coastline has more sewer systems with overflows and more paved surfaces that send contaminated runoff into the waters.
The water is tested at beaches from Memorial Day through Labor Day. At other times, the water could be clean or contaminated; it is not tested. Most sewage treatment plants along the coast disinfect their routine effluent discharges all year, but most treatment plants north of I-95 do not disinfect their effluent before May and after September.
How this indicator is calculated: The number of days that each coastal town and city closed one or more of its public beaches is added, and an average is calculated for all the coastal cities and towns with beaches. Because the bathing season is approximately 100 days long, the number of days shown on the top chart also equals the percentage of the bathing season when beaches were closed.
The Source of the Goal
The goal line on the top chart is an approximation of the target adopted in the 2015 edition of the Long Island Sound Study's Comprehensive Conservation and Management Plan. That plan's goal calls for cutting the number of beach closings in half by 2035 (from 2014, with the number for 2014 calculated using a five-year rolling average). The plan's goal is tied to individual beaches, while the indicator above counts beach closings by grouping together the beaches within each municipality. A fifty percent reduction in individual beach closings will likely result in a comparable reduction in the indicator above.
*Precipitation data are from the Bradley International Airport monitoring station.
**The changes in "approved" acres over the past decade have reflected changes in federal regulations and more accurate spatial measurement techniques in addition to water quality changes.