Hurricanes are rated in categories from number 1-5, with the higher the number, the stronger the hurricane. They can destroy everything in their path. Hurricanes can and do wreak havoc on the coastal marine ecosystems. They can mix up the water column, increase pollution via the runoff from storm water, destroy coral reefs, and redistribute bottom sediments. Hurricanes can also cause fish to evacuate nearby coastal ocean environments and near-shore estuaries, sending them towards deeper waters.
How Hurricanes Affect Fishing
When a hurricane hits, there can be a lot of dead fish, sea turtles, oysters, etc for a variety of reasons. It seems like the larger marine animals, like sharks, tuna, and dolphins, are hardly affected by a hurricane. They can detect the small changes in pressure as the larger waves on the surface approach and detect the reduced surface pressure that is associated with the hurricane itself. They may even leave the area or just swim deeper. Here are some of the ways in which hurricanes affect fishing.
Fish Trapped Because of Flooding
A hurricane not only affects the ocean and the marine life there but the rains from the hurricane can cause flooding on the shorelines and even inland. It can be so much rain that it floods areas that may not contain water or causes ponds, lakes, and rivers to overflow. When the water recedes, it is possible that the fish that were brought to an area by rising water become trapped and cut off from the main body of water. After the water that the fish have become trapped in dries up, the fish will also die. Sometimes the raging water will wash fish up on shore and then recede, trapping them there.
Changes in Salinities
After a hurricane, the saline storm surge or freshwater flooding from the rains could trap fish in an inappropriate salinity. Salinity is the amount of salt that is dissolved in a body of water or the saltiness of it. If the amount of salt in the water changes and the fish cannot escape, they could die if the species is intolerant to the changes in salinity.
This is the most common cause of the reason that so many marine life and fish die. When the oxygen level gets too low then they cannot get the required amount of oxygen for metabolism and to live.
Causes of Low-dissolved Oxygen
The oxygen manufacturing system uses energy from the sun to create carbon-based nutrition for the aquatic plants and microscopic organisms with oxygen as a by-product. After a hurricane, there can be a lot of cloudy days so as a result, there is less oxygen that is being produced. At night, because photosynthesis is not occurring, the aquatic plants and microscopic organisms are using oxygen during respiration just like all the fishes. When this happens, it does not take long for there to be little oxygen for the fish and other marine life. The oxygen levels are the lowest early in the morning so this is when most of the deaths occur.
In a pond or lake, the action of the wind could push the surface waters to one side of the pond or lake. Water from the bottom will rise to the surface to fill the space where it used to occupy. When this happens, this water will bring with it organic materials and sediment from the bottom. The water that comes from the bottom is low in oxygen and could bring with it hydrogen sulfide. It can be deadly to fish in high enough concentrations and is responsible for the sewage smell.
There can also be bacteria in the sediment that is brought to the surface and they will decompose any organic material that is brought up. When this happens oxygen is used up in the process. This is referred to as a “turnover”, which means that the bottom literally comes to the top.
How Hurricanes Affect Marine Life Under the Water
For some sea creatures and coral, a hurricane can be a death sentence, especially if they are territorial and will not leave their home to go somewhere safe. It is also a death sentence for slow swimmers like the seahorse. The powerful winds of a hurricane can also mix the cold deep waters of the ocean with the shallow warmer water so this can mess up a fish’s habitat and put them in water that is not suited for them.
The territorial or slow-moving marine life like oysters, sea turtles, and crabs will get smashed around by the waves and there is also less dissolved oxygen in the water because of the waves. The coral can die because the hurricane can rip them apart along with dumping a large amount of ocean sediment on them. The broken coral that does live is more susceptible to death and disease. If the coral reefs that have been ravaged by a hurricane live, it can take them 15-20 years to recover but some just never bounce back.
After a hurricane, it can take months, even years, to recover from the death and destruction it has caused to fishing. The ravaged coral, if it comes back, will take many years. A hurricane may only last minutes but the devastation left behind can be catastrophic and take years to return to normal. The one main thing in how hurricanes affect fishing is that the oxygen is low-dissolved and if the fish do not have oxygen, they will die. Many times some of the bottom-dwelling fish will feel stressed after a hurricane and will develop signs of disease like lesions and sores. With the coral reefs destroyed or damaged, many fish will have a hard time finding shelter and food.
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So there are many ways in which a hurricane affects fishing. Some that we know about but there could be other ways that scientists have not discovered. The fishing that is mainly affected by hurricanes is the slow-moving, territorial, and ones that live close to the shore and the coral.