Respuesta :
Mark Brainliest please
Throughout human existence we have relied on the oceans – for food, as a waste dump, for recreation, for economic opportunities and so on. However, it’s not only our activities in the marine environment that affect life in the sea – it’s also the things we do on land.
With more than half the world’s population now living within 100 kilometres of the coast, it’s not surprising that our activities are taking their toll. Human impacts have increased along with our rapid population growth, substantial developments in technology and significant changes in land use. Over-fishing, pollution and introduced species are affecting life in the sea – and New Zealand is no exception!
Threats to marine habitats
Human actions at sea and on land are putting increasing pressure on the ocean and the species that live there.
Fisheries
Humans living near the coast have probably always used the ocean as a source of food. However, with advances in fishing equipment, larger ships and new tracking technologies, many fish stocks around the world have reduced significantly. Fish stocks on continental shelf areas are now widely considered to be fully or over exploited. Aside from reducing fish stocks, unsustainable fishing practices can have other negative impacts on the marine environment. For example, some fishing techniques such as dredging and trawling can cause widespread damage to marine habitats and organisms living on the sea floor. These techniques also often capture non-target species (known as bycatch) that are then discarded.
Rights: Ra Boe, CC BY-SA 2.5
Commercial fishing boat
Fishing was probably the first use of the oceans by humans. In the last century, significant increases in commercial fishing have resulted in the over-exploitation of many fish stocks.
In New Zealand, fisheries are managed by a quota system that sets catch limits for commercially important species and aims at sustainable management of our fish stocks. The Royal Forest and Bird Protection Society (NZ) publishes the Best Fish Guide to try and encourage us to make more sustainable choices when purchasing seafood. The list evaluates fish stocks and bycatch levels and the fishing methods used.
Pollution
Our oceans have long been used as an intentional dumping ground for all sorts of waste including sewage, industrial run-off and chemicals. In more recent times, policy changes in many countries have reflected the view that the ocean does not have an infinite capacity to absorb our waste. However, marine pollution remains a major problem and threatens life in the sea at all levels.
Rights: Jeff Schmaltz, MOD IS Land Rapid Response Team at NASA GSFC
Phytoplankton bloom
This image shows a large phytoplankton bloom that occurred around New Zealand in October 2009. The image was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA’s Terra satellite.
Some marine pollution may be accidental, for example, oil spills caused by tanker accidents. Some may be indirect, when pollutants from our communities flow out to sea via stormwater drains and rivers. Some effects may not be immediately obvious, for example, bioaccumulation – the process where levels of toxic chemicals in organisms increase as they eat each other at each successive trophic level in the food web.
Link :
https://www.khanacademy.org/science/high-school-biology/hs-ecology/hs-human-impact-on-ecosystems/a/hs-human-impact-on-ecosystems-review
https://www.sciencelearn.org.nz/resources/144-human-impacts-on-marine-environments
Throughout human existence we have relied on the oceans – for food, as a waste dump, for recreation, for economic opportunities and so on. However, it’s not only our activities in the marine environment that affect life in the sea – it’s also the things we do on land.
With more than half the world’s population now living within 100 kilometres of the coast, it’s not surprising that our activities are taking their toll. Human impacts have increased along with our rapid population growth, substantial developments in technology and significant changes in land use. Over-fishing, pollution and introduced species are affecting life in the sea – and New Zealand is no exception!
Threats to marine habitats
Human actions at sea and on land are putting increasing pressure on the ocean and the species that live there.
Fisheries
Humans living near the coast have probably always used the ocean as a source of food. However, with advances in fishing equipment, larger ships and new tracking technologies, many fish stocks around the world have reduced significantly. Fish stocks on continental shelf areas are now widely considered to be fully or over exploited. Aside from reducing fish stocks, unsustainable fishing practices can have other negative impacts on the marine environment. For example, some fishing techniques such as dredging and trawling can cause widespread damage to marine habitats and organisms living on the sea floor. These techniques also often capture non-target species (known as bycatch) that are then discarded.
Rights: Ra Boe, CC BY-SA 2.5
Commercial fishing boat
Fishing was probably the first use of the oceans by humans. In the last century, significant increases in commercial fishing have resulted in the over-exploitation of many fish stocks.
In New Zealand, fisheries are managed by a quota system that sets catch limits for commercially important species and aims at sustainable management of our fish stocks. The Royal Forest and Bird Protection Society (NZ) publishes the Best Fish Guide to try and encourage us to make more sustainable choices when purchasing seafood. The list evaluates fish stocks and bycatch levels and the fishing methods used.
Pollution
Our oceans have long been used as an intentional dumping ground for all sorts of waste including sewage, industrial run-off and chemicals. In more recent times, policy changes in many countries have reflected the view that the ocean does not have an infinite capacity to absorb our waste. However, marine pollution remains a major problem and threatens life in the sea at all levels.
Rights: Jeff Schmaltz, MOD IS Land Rapid Response Team at NASA GSFC
Phytoplankton bloom
This image shows a large phytoplankton bloom that occurred around New Zealand in October 2009. The image was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA’s Terra satellite.
Some marine pollution may be accidental, for example, oil spills caused by tanker accidents. Some may be indirect, when pollutants from our communities flow out to sea via stormwater drains and rivers. Some effects may not be immediately obvious, for example, bioaccumulation – the process where levels of toxic chemicals in organisms increase as they eat each other at each successive trophic level in the food web.
Link :
https://www.khanacademy.org/science/high-school-biology/hs-ecology/hs-human-impact-on-ecosystems/a/hs-human-impact-on-ecosystems-review
https://www.sciencelearn.org.nz/resources/144-human-impacts-on-marine-environments
Answer:
Phascolarctos cinereus, or koala bears, are cute little animals native to Australia. Some people even call them the jewel of Australia. Koala bears are beloved by many because of their adorable faces, ash-coated fur, and their small, furry paws! Want to start learning more about koalas? To begin, let me start telling you more about their habitat, adaptations, genetic diversity, diets, and lifestyle.
Despite living in a variety of forested habitats, koalas are generally herbivorous, and they rely significantly on tall eucalyptus trees for food and shelter. The koala is a herbivorous animal. An adult koala can consume up to 500 grams of eucalyptus leaves per day. Did you know koalas do not drink water? This occurs because of the “large quantities of water in eucalyptus leaves.” In fact, their name Koala means "who do not drink" in the language of the Aborigines."
Koalas in the wild begin breeding between the ages of two and three for females and begin mating between the ages of two and three for males. “A female koala has the ability to reproduce for ten to fifteen years since the start of mating.” The breeding season for Australian koalas is spring and summer. Each female koala will have one offspring each year. “It takes about 35 days after conception for a baby Joey to be born, A Joey is a baby koala.”
Some koala facts are that a “koala can grow 60 to 85 cm long in their lifetime” and that an average koala’s “body weight ranges from around 4 to 15 kgs.” Male koalas also tend to have a 50% bigger body size than females! Did you know that “the oldest koala was 23 years old and lived from 1978 to 2001.” The koala’s name was Sara.
A koala has soft, thick, usually gray fur, sharp claws, and strong limbs. Most of these traits are koala adaptations, which means the animal may not have always looked this way in the past. Adaptations can be defined as "the process of adapting an organism or species to its environment." Now, let's learn about the koala bear’s adaptations. Due to their habitat, tall eucalyptus trees of eucalyptus, koalas have long claws and padded paws that make climbing and moving around trees easier for them. “Their claws and paws are adaptations they developed so they have an easier time climbing”. Koalas have “strong limbs that aid them in wrapping around trees” and staying there without falling, giving them a grip. Koalas also have an extraordinary sense of smell, and their odor assists them in determining whether or not eucalyptus leaves are toxic, thus helping them select or decide which leaves to eat. Due to koalas only eating eucalyptus leaves, they have really low energy, therefore they have adapted to use less energy for their body. Koalas have a small brain with a mostly hollow interior helping them use less energy. They also sleep for about 18 hours a day to conserve energy. These are just a few of the koala bears adaptations that have been helping it survive. Now let’s learn about the koala’s population!
Currently, Koalas are classified as vulnerable animals by the Australian government. However, many experts expect them to be listed as endangered animals in the near future. Seeing a koala's suffering is hard, both for the animals and for the people who love them. There is no estimate for the exact number of koalas in the world, but it is believed to be less than 80,000. During the early 1700s, millions of koala’s were known to have lived in Australia, but as “European settlers came to the country, the koala’s lost their habitat from their settlements and started to be hunted for their fur, as koala fur went for a lot of money making them a target for hunters. “During the late 1800s, koala populations declined by more than 50%. This was the beginning of the koala population decline.” In the 1870s and 1880s, as the Koala population declined, finding suitable mates became increasingly difficult, which led to inbreeding which has persisted until this day, significantly reducing genetic diversity.
Koala numbers have declined steadily over the past few decades following the arrival of settlers in Australia in the early 1700s, but the bushfires that raged through Australia from 2019 until 2020 have made the situation even worse for the animals there, which includes the koala.
The habitat loss caused by fires has reduced Koala numbers by 30 percent in just three years. Koalas are already declining at a rapid rate. As far as the species is concerned, koalas are almost endangered, so if this continues, they are likely to become extinct soon. It is predicted by some wildlife foundations that the koala species will disappear within 30 years if this decline rate continues.
