{"id":9339,"date":"2024-01-23T20:55:19","date_gmt":"2024-01-23T19:55:19","guid":{"rendered":"https:\/\/www.aboutriver.com\/?p=9339"},"modified":"2024-01-23T20:55:19","modified_gmt":"2024-01-23T19:55:19","slug":"how-far-have-sharks-swim-up-the-mississippi-river","status":"publish","type":"post","link":"https:\/\/www.aboutriver.com\/how-far-have-sharks-swim-up-the-mississippi-river\/","title":{"rendered":"How Far Have Sharks Swim Up The Mississippi River"},"content":{"rendered":"
Sharks have recently been tracked making their way up the Mississippi River, and researchers are intrigued as to why these towering, toothy-fringed fish are making their ascent up the inland waterway. Logically, one must wonder what is driving them up river? A few assumptions and theories have been proposed by experts and their research points us to the potential causes.<\/p>\n
It has been discovered that the sharks’ primary reason for undertaking this remarkable journey is the continuing northward movement of saltwater species due to climate change and higher water temperatures. This is forcing the sharks to increasingly seek out more comfortable habitats, leading them further and further upriver in search of cool, nutrient-rich waters.<\/p>\n
Scientists report that this migration goes as far as 270km (168mi) inland and the average shark is traveling upwards of 111km (69mi) per day in order to find the saltwater they require – an amazing feat!<\/p>\n
It is uncertain how long the sharks will be willing to travel upriver, however if the water temperatures continue to rise, as models predict, it is likely to provoke behavior in the sharks that causes them to range even further inland, further compounding their adaptation to freshwaters.<\/p>\n
The emergence of sharks in the Mississippi River is the first reported freshwater migration of saltwater invertebrates in the world. Although river sharks are being found in other waterway systems, i.e. the Hudson River, the species’ appearances are so far limited. As of yet, the combined numbers of migrating species to freshwaters are still marginal.<\/p>\n
In addition, it was initially expected that the fresh water of the Mississippi River would impact the sharks’ health; however, further study revealed that their remarkable adaptability and almost instantaneous readjustment to their new environment was incredible. It is clear that these predators are proving themselves to be formidable river sharks.<\/p>\n
It appears that, while the ocean is their natural habitat, sharks have evolved to be highly resourceful – a skill that will undoubtedly make them formidable species in the face of a changing climate. In response to becoming increasingly homeless, they are forging their own way forward and showing us a remarkable example of the strength of natural adaptation.<\/p>\n
The freshwater habitat of the Mississippi River is relatively nutrient-poor, but the sharks are knuckling down and proving more than capable of keeping themselves fed by relying on the migratory fish that enter the river in spring. As such, their diets appear to be plentiful and more diverse than what can often be found in the saltwater ocean.<\/p>\n
In an exquisite example of adaptation, the sharks have shown a significant shift in physiological and anatomical characteristics that assist with aiding their new lifestyle. Through evolution, their bodies have been adapted to living in freshwaters, including the need for swimming faster, increasing their fatty acid storage and persisting in lower oxygen concentrations. Tracking devices have enabled researchers to monitor their movements and gain accurate insights into their lifestyle. This has revealed that their physiology is not suffering due to their transition to inland dwellings.<\/p>\n
The sharks upriver appear to be thriving and experts believe that, because of their new environment, this could grant them even longer lifespans than those seen in their ocean counterparts. An impressive observation, especially considering their remarkable journey.<\/p>\n
Up until now, evidence has shown that shark populations have not been impacted by the freshwater conditions. However, researchers admit that their movements are monitored closely as they are vulnerable to the risks posed by human activity; particularly those associated with overfishing and water pollution.<\/p>\n
Fishing practices have proven to be much harder to control in freshwater habitats due to the lack of regulation of the inland areas. This could result in species in our rivers being overfished in a short period of time, as opposed to oceanic environments which can sometimes take years before species are endangered.<\/p>\n
Water pollution is something that both saltwater and freshwater species are vulnerable to, with much of the water in both environments being unsafe for consumption – a factor which can, unfortunately, heighten pressure on species’ thresholds. On the other hand, the world’s oceans are subjected to higher levels of pollutants than the rivers, resulting in higher levels of toxicity in the saltwater compared to the freshwaters.<\/p>\n
What is interesting to note, however, is that freshwaters of the Mississippi River have generally sustained much better health standards over recent years than their oceanic counterparts. It is likely, then, that the river sharks are enjoying a safer environment in the river than in their original habitat.<\/p>\n
Up until now, sharks have been legally off-limits to fishermen. Extensions of jurisdiction of Territorial Sea Claims are often limited to a certain number of nautical miles, beyond which they have historical claims of fisheries management. In the case of the Mississippi River, this policy could come into direct conflict as the majority of the waterway runs inland and has a higher exposure to human interference.<\/p>\n
This raises difficult questions regarding the applicable laws of freshwaters and the enforcement thereof. Research has demonstrated that the affected species is of a migratory ancestry, which presents a number of legal conundrums with respect to management and protection of species. This responsibility could be made more difficult due to their powerful swimming abilities, as well their ability to move upstream in ways that were not previously observed.<\/p>\n
It is clear, then, that legal complications will accompany the influx of these species, turning attention to the need for protection of these predators, as well as their right to pool-hopping liberty. Surprising as this may be, these creatures have a right to sustainable migration to cooler freshwaters in order to survive.<\/p>\n
In the face of salty challenges, levels of public concern have risen with reports of ‘river sharks’ making their way up the Mississippi. The perception of these predators has shifted significantly since their debut on rivers. Initially, reports of ‘monsters from the deep’ invoked great fear in coastal towns and further cause for alarm as to why the species of potentially dangerous fish were taking up residence in rivers. Soon, however, this concern was replaced by admiration for their incredible journey, with awe inspiring tales of sharks swimming upstream of a river being shared far and wide.<\/p>\n
This transition of fear to admiration has been largely due to the efforts of expert researchers who have studied the species’ transition and enabled us to observe this fascinating species making their inspiring transition. By educating people on the beauty of migration and the importance of the right to mobility in order to survive, people’s perspectives of environmentalists and conservationists have also been reshaped.<\/p>\n
Previously, people looked to the ocean to revel in the magnificence of sea life and the powerful predators within. Now, attention has been diverted toward rivers, setting an example for us of the ongoing adaptability of species in the face of climate change. We should look upon the movement of these species with admiration, rather than fear; highlighting the importance of educating ourselves on the mesmerizing and inspiring power of adaptation.<\/p>\n