Chatham Rise facts for kids
The Chatham Rise is a large area of the ocean floor located east of New Zealand. It is part of the Zealandia continent, which is mostly underwater. This underwater rise stretches for about 1,000 kilometers (620 miles) from near New Zealand's South Island all the way to the Chatham Islands. It is super important for fishing in New Zealand and is also a key home for whales.
Compared to other parts of the Pacific Ocean around New Zealand, the Chatham Rise is quite shallow. It's never deeper than 1,000 meters (3,300 feet). This is surprising because the ocean gets much deeper very quickly right next to it. To the north, the Hikurangi Trench drops to more than 3,000 meters (9,800 feet). To the south, the Bounty Trough also reaches similar deep levels.
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What is the Chatham Rise?
An Ancient Landmass
Geologists think the Chatham Rise is like an underwater extension of New Zealand's eastern South Island. A long time ago, about 66 million years ago, this area was mostly dry land. It formed a huge peninsula that connected New Zealand to the Chatham Islands.
This ancient land was covered in volcanic landscapes. Scientists have found fossils on the Chatham Islands that tell us about the plants and animals that lived there. There were forests with plants like Araucaria and Podocarpus, and also clubmosses. Some flowering plants were also present. Even dinosaurs, like theropods, lived on this peninsula! They probably developed into unique kinds found only there.
Why is the Chatham Rise Important for Fishing?
The Chatham Rise is New Zealand's most important place for commercial fishing. It's a bit like a famous fishing spot in the North Sea, but much deeper.
Where Warm and Cold Waters Meet
The reason it's so good for fishing is because of something called the Subtropical Front. This is where warm waters from the north meet cold waters from the south. When these waters mix, they create perfect conditions for tiny sea creatures called plankton to grow. Fish love to eat plankton, so lots of fish gather here.
New Zealand's Main Fishing Ground
Because the Chatham Rise is relatively shallow, fishing boats can use different methods to catch fish. They use both midwater trawling (catching fish in the middle of the water) and bottom trawling (catching fish near the seafloor). About 60% of all the fish caught in New Zealand come from the Chatham Rise.
Many different kinds of fish are caught here. These include hoki, hake, ling, silver warehou, squid, orange roughy, and deep-sea dory.
Protecting Our Fish
Fisheries management is about making sure we don't catch too many fish. If too many fish are caught, it can harm the breeding population and affect the whole ocean. Scientists are now looking at the entire food chain in the ocean. They study what different fish species eat by looking at over 40,000 fish stomachs from the Chatham Rise!
These studies, along with research on marine mammals, seabirds, and ocean conditions, help us understand how everything fits together in the Chatham Rise ecosystem. This way, we can protect all the amazing marine life that calls this area home.
Images for kids
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Phosphorite from the Chatham Rise
See also
In Spanish: Elevación de Chatham para niños
