The salmon spend about one to five years (depending on the species) in the open ocean, where they gradually become mature. The adult salmon then return to the streams where they were born in order to breed. Atlantic salmon spend between one and four years at sea. Some species of salmon grow a hump on their back or bigger teeth before they start breeding. All change from the silvery blue of an ocean salmon to a darker colour. Salmon make amazing journeys. They migrate huge distances up rivers in their hundreds and thousands in order to breed. Swimming upstream to get to their birthplace where they can reproduce takes a huge amount of effort as the fish must swim against strong currents and rapids. Chinook and sockeye salmon from central Idaho, for example, travel over 1,400Â km and climb nearly 2,100Â m from the Pacific Ocean as they return to spawn. The condition of the fish tends to deteriorate the longer they remain in fresh water, and they then deteriorate further after they breed, when they are known as kelts. Mature Salmon typically die within a few days or weeks of breeding.
Freshwater streams and estuaries on the coast provide an important habitat for many salmon species. They feed on insects, and crustaceans while young, and primarily on other fish when older. Estuaries and their associated wetlands provide vital nursery areas for the salmon before their departure to the open ocean. Wetlands not only keep the estuary clean from pollutants, but also provide important feeding and hiding areas. As wetlands habitats are damaged or converted for human use, there has been a sharp decline in the number of salmon. This has led to some species of salmon becoming endangered and being protected by law in certain countries.
1. | When the are born they are fully independent and don’t need the parent’s protection |
2. | destruction is causing many animals to become extinct. |
3. | The new factory opened and the quality of the air in the town . |
4. | Many birds thousands of kilometers every year. |
5. | Despite being quite small, a king cobra still has enough venom to kill several adult humans. |
6. | You can find lots of frogs and toads in the and lakes close to my house. |
7. | Before we went camping in Canada we had to learn how to if a bear attacked us. |
8. | Don’t swim in an in a tropical country because it may contain crocodiles or bull sharks that come to feed on the fish and mammals which live there. |
The salmon spend about one to five years (depending on the species) in the open ocean, where they gradually become mature. The adult salmon then return to the streams where they were born in order to breed. Atlantic salmon spend between one and four years at sea. Some species of salmon grow a hump on their back or bigger teeth before they start breeding. All change from the silvery blue of an ocean salmon to a darker colour. Salmon make amazing journeys. They migrate huge distances up rivers in their hundreds and thousands in order to breed. Swimming upstream to get to their birthplace where they can reproduce takes a huge amount of effort as the fish must swim against strong currents and rapids. Chinook and sockeye salmon from central Idaho, for example, travel over 1,400Â km and climb nearly 2,100Â m from the Pacific Ocean as they return to spawn. The condition of the fish tends to deteriorate the longer they remain in fresh water, and they then deteriorate further after they breed, when they are known as kelts. Mature Salmon typically die within a few days or weeks of breeding.
Freshwater streams and estuaries on the coast provide an important habitat for many salmon species. They feed on insects, and crustaceans while young, and primarily on other fish when older. Estuaries and their associated wetlands provide vital nursery areas for the salmon before their departure to the open ocean. Wetlands not only keep the estuary clean from pollutants, but also provide important feeding and hiding areas. As wetlands habitats are damaged or converted for human use, there has been a sharp decline in the number of salmon. This has led to some species of salmon becoming endangered and being protected by law in certain countries.
A | The female creates a 1. in the gravel of a stream bed. |
B | Constantly flowing water keeps the eggs oxygenated and at the correct temperature. |
C | Newly hatched juveiles escape predators by hiding amongst 2. . |
D | After becoming smolt, they move downstream to the ocean or sea. |
E | It takes up to 5 years for salmon to become 3. in the ocean or sea. |
F | Adults return to their natal streams to 4. . |
G | After reproducing, salmon generally 5. quickly and then die. |
Remember that when you make mistakes it is important to think about why the mistakes are made. If advanced vocabulary stops you from understanding the text or a question, you need to develop that part of your English. The same is true if complex grammar causes you to misunderstand what the question or the text is communicating. Careful analysis of your weaknesses is a very efficient way of improving your English!
Our final lesson of the course is next, where we will look at yes/no/not given and multiple choice question types.