Fjord | Oceana
Would you like to view our US Site?

Marine Science and Ecosystems

Fjord

Distribution

Cold temperate to polar latitudes of the north Atlantic, north Pacific, and south Pacific oceans

Physical Ocean Characteristics

Long, deep, narrow inlets surrounded by steep cliffs, often with strong tides

Keystone Species

Cold-water corals and sea anemones, Killer Whales, seals, salmon

Ecosystem Services

Fisheries, ecotourism, aquaculture, artisanal hunting

Share

Facebook Twitter Pinterest Google+

Fjords are long, narrow, deep bodies of water along the coasts of formerly glaciated areas. As glaciers historically flowed to the coast, they eroded deep, sharp canyons. Fjords were created once the glaciers melted and the canyons were flooded by rising sea levels. These marine ecosystems are typically surrounded by tall mountains with steep sides that continue below the waterline.

As a result of these steep sides, fjords can reach extreme depths only a few meters from shore; the deepest fjords are up to 6300 feet (nearly 2000 m) deep.  The long, narrow nature of fjords means that they may extend far inland from the coast; the longest fjords extend hundreds of kilometers inland. 

Most fjords are found in the northern hemisphere, which was the half of the planet most significantly covered by glaciers during past ice ages.  They are most often found in northern Europe, Greenland, and Canada.  However, fjords can be found in some areas south of the equator that are near coastal mountain ranges, most notably New Zealand and Chile.

These unique systems allow deep-sea organisms to live close to shore, even somewhat inland, a fact that is abnormal or impossible along typical coasts.  Deep-water coral reefs are also often found in fjords.  Most coral reefs are tropical and occur in shallow, clear water.  Recently, however, coldwater corals have been discovered on deep seamounts and in deep fjords, in cold temperate or sub-polar waters.  Reefs in both northern and southern hemisphere fjords are characterized by extremely old, slow growing corals (e.g. Lophelia pertusa or Desmophyllum dianthus) and anemones that support a diverse ecosystem of other invertebrates and fishes. 

Other charismatic species that regularly utilize fjords include killer whales and other whales, Greenland sharks, several species of seals, and several different salmon species.  These species are the top predators in fjord food webs, which also include numerous species of forage fishes and other prey.

As some fjords do not flush regularly, pollution is the primary threat to fjord ecosystems.  Invasive species can also be a problem in these systems.  Like in any marine ecosystem, destructive fishing practices can threaten fjord habitat and risk fisheries on fjord species.

 

Pages

the Full Creature Index