Recreational fishing is important! Not only does angling provide a wonderful hobby for millions of participants, it is also crucial to many local and national economies. Those who run fishing lakes, sell fishing gear or organise fishing trips make their living from angling. Fishing opportunities boost regional coffers and rod licenses generate funds for the treasury. So, fishing matters, even to those who do not fish. But angling could be seriously threatened by climate change.
Concerns Spark Research into the Future of Fishing
Scientists have started to study the potential impacts of climate change on fishing and their efforts have been driven by concerns fort the financial implications and the impact on biodiversity. ore research is needed as there are so many variables to consider, but it is becoming clear that climate change has already impacted fishing and the situation is likely to get worse.
Higher temperatures globally are causing water temperatures to rise. Coldwater fish are particularly sensitive to temperature changes and so it should come as no surprise to find that they are diverting from some rivers into any available lakes and ponds where the water is colder. Warmer waters are attracting non-native species, some of which are predatory. There has also been an increasing prevalence of bacterial disease which is leading to greater fish mortality. Unfortunately, it isn't known precisely how sensitive fish are to temperature change and whether they are able to adapt over time to the new conditions. It is possible than many species will simply die out.
The situation is made worse by the decrease in snow fall in the winter months. Less snow and warmer temperatures mean an earlier melt in spring and lower water levels. Ice fishing is a popular pastime in North America but many lakes are now failing to freeze over in winter. Increases in temperature also result in changes to water circulation patterns. This can cause a rise in nutrient concentration. The consequence is an imbalance in the ecosystem which will impact freshwater fish.
Climate change is increasing the incidence of extreme weather events. Flooding is becoming more common and can disrupt spawning. Periods of drought occur more often, reducing water levels, exacerbating the increases in water temperature and raising the likelihood of fires.
Fires and Fishing
As trees burn and fall, the sediment erodes into nearby bodies of water. This new type of waste material fills in spaces where fish would usually lay eggs and can, in some cases, damage their gills. migration routes may also be blocked or altered by the debris. Fires also produce by-products including nitrogen, phosphorous and potassium. These nutrients are beneficial to the food base of most fish, but in excess, they can create algae blooms which in turn deprive the water of light and oxygen. This would obviously have a negative impact on the health of fish stocks. Our efforts to control wildfires can mean that toxic substances are introduced into the environment. Fire retardants containing water-soluble ammonium salts, industrial strength fertiliser, and dyes are needed to halt the progress of a fire and protect communities. However, it is possible that ammonium phosphate could be harmful to many species of fish. It is predicted that habitats for Coldwater fish could decline by more than 50% by the end of the century. It is vital that we gain an better understanding of how climate change impacts fish and that we all do our bit to help the environment.