background preloader

Rocky Shore

Facebook Twitter

UK Rocky Shores. The UK’s expansive coastline, which is well over 6,000 kilometres long, varies dramatically and presents a number of different rocky habitats, ranging from calm, sheltered coves and rocky beaches to tall, imposing cliffs.

UK Rocky Shores

Within each of these rocky habitats the conditions are highly dynamic, due to the ever-changing tides (1) as well as additional environmental factors such as temperature and wind (2). Rocky shores are formed when waves erode softer rocks, leaving harder rocks exposed (3). Marine habitats are often divided into several zones, which are based on their position in relation to the tide.

Zones of a rocky shore – Coastal shoreline. Rock Pool Creatures. These small crabs swim around in rock pools or crawl along the bottom looking for food.

Rock Pool Creatures

They are scavengers, which means they mostly feed on the bodies of dead animals. Cushion stars are starfish with short arms, which makes them look soft and plump. They crawl around rock pools eating small sea snails and worms that live on the rocks. Anemones have long tentacles that drift in the water. They may look pretty, but the tentacles are equipped with tiny, venomous barbs that catch and kill small creatures that swim into them. Prawns are small crustaceans that swim around the shoreline. When water covers them, beadlet anemones open out their tentacles, waving them gently through the water to catch passing prey. Protected by a spiny shell, the sea anemone crawls along the bottom of the pool. This green growth may look like a plant, but it is actually an animal called a sponge.

When the water covers them, limpets crawl around looking for seaweed to eat. BBC Nature. Intertidal. The intertidal area (also called the littoral zone) is where the land and sea meet, between the high and low tide zones.

Intertidal

This complex marine ecosystem is found along coastlines worldwide. It is rich in nutrients and oxygen and is home to a variety of organisms. An Inhospitable, Changing Environment: Much of this inhospitable environment is washed by the tides each day, so organisms that live here are adapted to huge daily changes in moisture, temperature, turbulence (from the water), and salinity.

Moisture: The littoral zone is covered with salt water at high tides, and it is exposed to the air at low tides; the height of the tide exposes more or less land to this daily tide cycle. Organisms must be adapted to both very wet and very dry conditions. Vertical Zones: The littoral zone is divided into vertical zones. Canada's Rocky Shore. Lichens This unique plant is half algae, half fungi!

Canada's Rocky Shore

©Parks Canada / G-4 What are all the gray, green, orange and black "paint" splotches on the rocks in the splash zone of the beach? They're various species of lichen! These unique plants-half-algae, half-fungi-slowly dissolve rock, creating soil that will allow more complex plants to grow in the area. Some lichens are fragile and crumbly when dry, but are very slippery when wet; so for their safety and yours, avoid stepping on them if you can.

Sea Palm (Postelsia palmaeformis) Sea palm survive in the "impact zone" by anchoring to rocks©Parks Canada / M. Your eyes haven't tricked you if you see palm trees at the edge of the sea; but when you do see them, beware. Unfortunately humans aren't made of rubber and can't survive what the sea palm can survive. Gooseneck Barnacles (Pollicipes polymerus) Gooseneck barnacles can be found on surf-swept rock©Parks Canada / M. These barnacles, like sea palms, live in areas with strong surf. Coastal shoreline. Rock pools and surge channels are good places to observe life in the low-tide zone.

Coastal shoreline

At first glance, animals may be difficult to detect, for many are camouflaged, or hide under rocks and in crevices. The most mobile are small fish, of which there are at least 40 species. Cockabullies or common triplefins (Forsterygion lapillum) swim about in search of any small animal to eat. The nearly transparent shrimp (Palaemon affinis) is also a fast mover when it detects a scrap of food. Found crawling about the sides and bottom of the pool are whelks (Cominella species), common predators of other shellfish.

Encrusting or attached animals live in rock pools and the lower tidal zone. Two species that are now uncommon in accessible rock pools and reefs are the edible abalone pāua (Haliotis australis) and kina, the sea urchin (Evechinus chloroticus). Bright eyes A traditional use of pāua shell was as inlay for eyes in Māori carvings – the iridescent colours have a life-like quality. Stony beaches.