As the Amazon River region's prized rainforest continues to dwindle, the river itself now bears witness to another threat: freshwater fish overexploitation.
As per a large-scale, pan-Amazonian study done by a consortium of international experts led by Cornell University academics, the richness of the Amazon's freshwater species is under severe fishing pressure.
They discovered stress that threatens the region's capacity to deliver protein and other critical elements after reviewing decades of fisheries landings in areas like ports where fishermen deposit their catch records from Brazil and Peru.
Population Decline of fish species in amazon river
JAM STA ROSA/AFP via Getty Images
Large-bodied species are declining, according to main author Sebastian Heilpern, a Cornell Presidential Postdoctoral Fellow who collaborated with associate professor Peter McIntyre and professor Alex Flecker, both of the College of Agriculture and Life Sciences, as per ScienceDaily.
Large-bodied animals are more susceptible because they mature more slowly, and smaller species are replacing the bigger ones as their population dwindle, according to Heilpern.
Overexploitation is consistent with this tendency.
Harvests may be sustained, according to Heilpern, as fish species are replenished.
However, information from scientific models suggested that harvests may eventually fail.
The continuous reduction of fish biodiversity diminishes the pool of compensatory species, reducing fisheries' resilience even more.
Overfishing is effectively depleting the natural sustainability savings account and biological security provided by variety.
According to Heilpern, there is a bank of fish species that can compensate for the loss of one species. However, when the bank is exhausted, compensating potential loses.
It showed that the level of sustainability is dwindling.
According to the report, the Amazon River is one of the most productive and diversified freshwater ecosystems on the globe.
The region's residents consume some of the world's highest levels of fish, averaging roughly 110 pounds per person per year.
Overfishing or overexploitation is the removal of marine living resources to levels that are insufficient to support viable populations, as per Marine Species.
Overexploitation can eventually lead to resource depletion and the extinction of a number of vulnerable and endangered species.
To fulfill the increased need for food, the exponential rise of the human population over the last few decades has resulted in overexploitation of marine life resources.
Fishing fleets are two to three times the size required to capture current fish and other marine species, as well as what our oceans can sustainably support.
Overfishing has an impact on not just open ocean and pelagic ecosystems, but also coastal and intertidal zones.
Intertidal limpets in Hawaii (Cellana spp. ), the Azores, Madeira, and the Canaries (Patella spp.) have all seen decreases, with significant population collapses documented in the Azores due to collection by local people.
When target species recruitment is strong, the average size of individuals is impacted because larger individuals are picked more frequently, and populations show evidence of growth overfishing.
When adult populations are excessively exploited, their number and size (spawning biomass) are decreased to the point where they lack the reproductive potential to replace themselves, resulting in recruitment overfishing.
As per a 2020 Food and Agricultural Organization (UN) assessment, the percentage of freshwater fish populations with biologically sustainable levels was 90% in 1990.
By 2017, however, sustainability had declined to 65.8%.
To sustain fisheries in the Amazon, Heilpern's article proposed that stronger monitoring, regulatory enforcement, and governance are required.
He also stated that extending protected areas can help to preserve habitats that are vital for many fish species.
