ROCKY SHORE BEACH BIOME Where are Rocky Shore

ROCKY SHORE BEACH BIOME

Where are Rocky Shore Beaches?

Rocky shores are quite common along the coast of the United Kingdom, making up 34 percent of the total shoreline. Rocky shores can be spotted all over the United Kingdom, including the northern stony sea loch inlets and much more exposed coasts on the Atlantic ocean. Parts of the Durham area, for example, are bordered by rocky cliffs formed by limestone.

The northwest coast of the United States features a great deal of notable rocky shore ecosystems. California's extensive coast can claim a handful of its own, including the areas of Monterrey Bay, Big Sur, Pacific Grove and Carmel. In Washington, rocky coast lines are the norm along the San Juan islands as well as the protected shores of the northern Puget Sound. Parts of the United States' New England coast are characterized by their rocky shore ecosystems. In fact, north of Cape Cod, Massachusetts, rocky coastlines dominate New England shores. Maine's coast, in particular, is known for its rocky shore coastlines covered with such creatures as mussels and barnacles. Much of Connecticut’s rocky shore, on the other hand, is populated predominantly -- and in some cases, almost exclusively -- by algae.

California

Cape Cod- Massachusetts

How are Rocky Shores formed?

Rocky shore beaches are formed when waves erode softer rocks, leaving harder rocks exposed. The dramatic mixed, semi-diurnal tidal cycle exposes invertebrates and algae to large fluctuations in temperature, desiccation, and wave action, with two high and two low tides per day. Rocky shores have a high permeability and much of the upcoming wave percolates into the bottom. This reduces the outwash of sediment toward the sea. For this reason, coarse sediment can accumulate on the beach and can be transported further on the beach by stronger waves.

There are two main types of rocky shores. Both these types of rocky shores also contain habitats such as platforms, rock pools and boulder fields, each containing their own unique species of fauna and flora. The two types of rocky shores are high energy shorelines generally exposed to open seas and low energy shorelines generally located in sheltered bays. Plants and animals in rocky shores grow in different areas (zones). Plants grow in areas depending on their ability to withstand time in and out of water (inundation and desiccation). Plant growth zones are usually quite evident due to the stationary nature of plants. Although animals have similar zonation also based on their ability to withstand water inundation, sun and air exposure, animal zonation is not as obvious because they are generally mobile.

In the splash zone or supralittoral fringe on exposed beaches, animals and plants that must be tough and immune to long term desiccation. Located right above the barnacle zone, black lichens, a crab known as the common sea slater, and the small periwinkle are the most common organisms found here. The upper littoral zone is found right below the supralittoral zone and contains mostly barnacles, but the dominant type is dependent on the conditions and geographical location. Balanus balanoides is the primary northern barnacle, while Cthamalus Stellus is the dominant southern species. The mid-littoral zone is found next. This area is still primarily barnacles, but the common mussel accompanies it. The bladderwrack can also exist here, although heavily damaged and misshapen. Some species of limpet and even anemones are found in this zone. The lower-littoral zone is mostly rock pools which primarily consist of the coral weed, anemones, and limpets. The sub-littoral fringe is only uncovered at uncommonly low tides and is dominated by large brown seaweed and murlin.

The main difference between the organisms of sheltered and uncovered rocky beaches is the growing dominance of seaweeds. The supra littoral fringe of the sheltered beaches is further down that of exposed beaches, but otherwise the flora and fauna and very similar. The upper-littoral Zone contains barnacles and a seaweed called the channelled wrack competing for space. The mid-littoral zone has competition between wracks and limpets. Periwinkles also live in this zone, but not in the abundance of the wracks and limpets. The lower littoral zone is dominated by the horned wrack and coral weed. The spirorbis worm also lives here plastered on the horned wrack. The sub-littoral zone is a kelp forest.

What does a rocky shore food chain look like?

Herring Gull Edible Crab Seaweed Common Limpet

How do humans use the rocky shore biome?

The primary use of this biome by humans is visitation and harvesting.

What threatens this ecosystem?

Harvesting pressure and disease can cause declines in rockyshore invertebrates, including abalone, mussels and limpets. The high visitation levels that occur on rocky shores in Southern California have caused changes in the diversity and abundance of intertidal organisms. Impacts from oil spills are difficult to generalize because spills vary greatly in amount, chemical composition and degree of weathering before reaching the shore. Research suggests that oil should be kept off shorelines and that cleaning oil from the shoreline can slow intertidal assemblage recovery. Physical abrasion from ship groundings can cause very localized damage to organisms and substrates. Debris from coastal development and coastal highway maintenance can create periodic disturbances that simulate landslides. These events can immediately eliminate habitat or have long term impacts related to sand movement and burial on adjacent sites.