The rocky shoreline lies between the lowest and highest tidelines. It is characterized by high wave action, constant submersion and exposure, changing temperature and salinity, and the occurrence of tidepools. The rocky intertidal habitat is host to many organisms that are capable of withstanding this harsh, ever-changing environment. Those organisms include green, brown, and red species of algae, sponges, sea anemones, barnacles, crabs, lobsters, starfish, whelks, mussels, sea urchins, and tunicates.

The rocky intertidal shoreline protects developed areas from intense wave action. It also provides recreational opportunities, such as fishing, birding, tide-pooling, and relaxing, and also attracts tourists to the aesthetic views of the coastline.

Shoreline construction of bridges, piers, and jetties changes water flow and sunlight levels. This can lead to changes in species composition. Coastal development can also lead to the destruction of habitat. Changes in water patterns from development may increase or decrease water flow. Contaminants, such as heavy metals, hydrocarbons, wastewater, and stormwater, can add to water quality degradation. Marine debris can choke and entangle marine life, in addition to being unattractive.

Over-harvesting of certain species, such as lobster, seaweed, and sea urchins, and erosion and habitat destruction from increased tourism and foot traffic can also cause problems.

For more information contact the New Hampshire Coastal Program at (603) 431-9366 or visit www.des.nh.gov/coastal.