pollution and restoration

what is bioaccumulation

the gradual buildup of chemical substances in the tissues of organisms over time

organisms can receive these chemicals through absorption, ingestion or contact

when does the process of bioaccumulation become significant

when organisms that hv absorbed or ingested these chemicals, are consumed by other organisms in the food web

  • this leads to the transfer of pollutants in higher trophic levels, and increases the accumulation


what is biomagnification

the increase in concentration of a substance, at higher levels of the food chain

  • as consumers consume organisms that contain these substances, the substance becomes more concentrated in the tissues of these higher-level predators


whats an example of bioaccumulation

mercury

  • human activities, such as burning fossil fuels, hv increased its release into the ecosystem

  • organisms cannot metabolise or excrete mercury, so it binds to proteins & becomes incorporated into tissues, where it accumulates over time

  • organisms in higher tropic levels consume the affected lower trophic organisms, resulting in an accumulation of mercury from each prey item

  • leads to magnification of mercury concentration as it moves up the food chain


note - plastic is a synthetic product that is non-biodegradable, meaning it can accumulate in soil & water bodies, endangering and harming wildlife & polluting environment

microplastics are small plastic particles or fragments

macroplastics are larger pieces of plastic that can be seen with the eye

plastic travels to other locations primarily by human activities, such as littering, improper waste disposal, runoff & spills

Great Pacific Garbage Patch - area of a high concentration of marine debris, primarily composed of plastic

  • isn’t a solid mass or an island of trash, but rather a collection of floating microplastics, macroplastics & other waste materials


whats one way that plastic disrupts marine food webs

consumption

smaller organisms filter-feed on microplastics, and these small organisms are consumed by other organisms

  • this results in a transfer of plastics, which can affect growth, survival of a species & reproductive success

  • the plastic can also bio magnify as it moves up the food chain, endangering the lives of higher-level predators (such as humans)


chemical pollution by plastic

plastic can absorb & release harmful chemicals

microplastics can also act as carriers - potentially contaminating remote locations

wildlife entanglement & ingestion by plastic

marine animals can become entangled in plastic & may mistake plastic as food and eat it

entanglement can cause death, amputation, or serious injuries

ingestion of plastic can cause internal injuries, block the digestive system, result in malnutrition & starvation

habitat degradation by plastic

plastic debris can damage marine habitats, such as seagrass beds & coral reefs

accumulation of plastic = damage done to sensitive habitats, effecting their ability to provide shelter, food & act as breeding grounds for marine organisms

plastic can also hinder or alter the light & nutrient dynamics in the water, affecting the overall health of ecosystems

whats rewilding

an approach to conservation & ecosystem restoration that involves the reintroduction & restoration of natural processes & biodiversity to ecosystems that have been affected by human activities

what’re some methods of rewilding

species reintroduction - bringing back keystone species, such as apex predators or large herbivores

habitat restoration - aims to provide suitable conditions for native species to thrive & facilitate natural processes within ecosystems

  • can look like reforesting areas, removing invasive species, restoring wetlands & constructing wildlife corridors

rewilding urban areas - reintroducing nature into cities or urban environments (creating rooftop gardens or habitats for wildlife within urban areas)

rewilding river & waterways - restoring natural processes in rivers & waterways

  • can look like removing dams or weirs, or restoring meanders

ecological management & natural processes - rewilding emphasizes allowing natural ecological processes to occur with much human intervention

  • can look like reducing intensive farming practices or reducing pesticide usage


whats an example of rewilding or restoring habitats

the Hinewai Reserve

  • in the 1980s, the Banks Peninsula was dominated by pastureland, with only a few patches of native vegetation

  • restoration efforts at Hinewai focused on allowing nature to retake & facilitate natural regeneration processes

  • the conservation team used a hands-off approach

    • removed grazing livestock, stopped the use of herbicides & allowed the land to naturally recover

  • over the years, native vegetation has begun to reclaim the land, with a diversity of indigenous plant species

    • this has attracted native wildlife species