. Now

The school works and essays from secondary school
Search schoolwork

Salmon

Subject: Biology , Animal
| More

Species description

Marking: The salmon has a special adipose fin, see picture.

The salmon has a silver shiny and shimmering green back with black spots. The male also has a vast underkäkskrok. Salmon is very lix trout but skilljer itself by its slimmer body, smaller more pointed head, thinner tail pole and that the trout will never be a silver shiny back.

Environmental

The Baltic salmon in the Baltic Sea, for Sweden in the east and south coast, with spawning in the northern rivers and streams in Blekinge. The Baltic salmon can probably also spawn in shallow, energized gravel banks in the east.

The Baltic salmon in the Baltic Sea is affected by the M74 syndrome that makes all the fry get malnutrition and die. More recently, other groups of substances that polybrominated diphenyl ethers (PBDEs), a type of flame retardant, has been discussed as a widespread environmental pollution in Baltic Sea fish. Unlike PCBs and DDT have PBDE concentrations have increased since the 1970s.

It is very popular to fish for salmon, eg in Mörrums river in Blekinge or rivers in northern Sweden. In Mörrums river in Blekinge overfished in 2005 up 3 tons of salmon, and in Gaula, Norway fished it up all over 38ton salmon!

Humans affect salmon spawning by building hydropower plants in the rivers so that the salmon can not swim up through the flowing rivers and lay eggs.

The salmon have different a niche in its levnadsliv. In September, November so the salmon swim up the rivers to spawn. Then it has a niche in streams with sandy and rocky bottoms.
When the eggs hatch, so stop youths left in the rivers up to 5 years, later to wander out into the Baltic. When the salmon are born so it lives in mass "älvstadier" where it is called parr, smolt, laxbarn, Orval, blanköre, shiny trout then called rise from the sea in the sea.

Feeding

When unglaxarna live in rivers will eat the snails, clams, insects and fish eggs.
When the salmon come out of the sea, the Baltic Sea for our part so the salmon's diet consists of sprat and herring, but also stickleback
occur regularly

Nutrition Pyramid salmon

Food web

Distribution

The salmon in Sweden found all along the east and south coast, in rivers and in Lake Vänern. 1959 was implanted in the Siljan and lake. Salmon populations are in the ocean's free water, rivers and for some populations even lakes.

Salmon stocks have always varied. Laxstammarna has fallen sharply since man began to build hydroelectric plants. This has meant that almost all the Baltic wild salmon strains are extinct today. Salmon stocks varies still much in between. Salmon in several of the northern rivers experienced a marked recovery in 1996-1997. This was due to several salmon fry survived a few years earlier

Propagation

Salmon belong to migrating fish. It reproduces in flowing rivers, but its real growth areas are in the ocean. During the 2000s played the salmon for our part in the 18 rivers flowing into the Baltic Sea. Today multiply salmon naturally only in two rivers that flow into the Baltic Sea, namely the Torne River and Simojoki. The reason why the salmon's lekvattnen disappeared is that power plants built in the gammla salmon rivers. Inland salmon spawning is now entirely destroyed, so their propagation entirely dependent on fish farming.

The animal's future

Salmon's future is uncertain. According to some it will probably salmon extinction just like the tuna here in Sweden. Self, I think that the salmon will be eradicated for the overfishing.

based on 11 ratings Salmon, 3.9 out of 5 based on 11 ratings
| More
Rate Salmon


Related schoolwork
The following are school projects dealing with salmon or in any way related with salmon.

Comment on Salmon

« | »