Few people know that March 3 was World Wildlife Day, or this coming Sunday (April 22) is Earth Day — perhaps Trump sucking up all the media oxygen is responsible. The fact remains, world wildlife is under serious threat, and in ways we can't even imagine — not forgetting the eventual disaster due to climate change, unless the world wakes up.
This Science article looks at plastic waste entering the oceans — often through catchment areas and into rivers that flow to the ocean. It assesses the influence of such waste on disease in reef-building corals. The authors survey 159 coral reefs in the Asia-Pacific, a region containing 55.5 percent of global reefs and 73 percent of the human population living within 50 km of a coast — about a quarter billion people.
Our plastic bag finally reaches the ocean and microbes hitch a ride on it, living longer and increasing their chances of landing on an unfortunate host: a coral reef. The authors have measured plastic items per 100 square meters. The count can vary from a low of 0.4 in Australia to a high of 25.6 in Indonesia. Size of human population in coastal regions, good management or mismanagement of plastic waste disposal are all factors in the amount of waste entering the water.
The study results are striking. The likelihood of disease from the microbes rises from 4 percent in areas free of plastic to a whopping 89 percent average when the corals have such debris. Another major issue is coral structural complexity which, importantly, underpins micro-habitats for reef-reliant organisms. Unfortunately, the study also finds that plastic debris is up to 8 times more likely to affect reefs with greater structural complexity. The resulting lack of habitat can devastate fisheries through a drop in productivity by a factor of three. Thus public awareness here could be a critical factor.
The scientists develop a human footprint index (HFI) comprising multiple aspects of human influence: built environment, croplands, pastures, nighttime lights, roads, waterways, railroads, population density, etc. On the animal side, they note and separate the effects of resource availability and body mass on vagility (migration distances) -- larger species travel further as do carnivores.
Pointing to the rapid global growth in managed bee colonies and the attention devoted to them, the authors believe this focus reduces efforts to preserve wild pollinators so necessary for wild plants and flowers. In fact, high densities of such bees worsen the decline of these wild pollinators, and have also been linked to the spread of disease via shared wild flowers. Long term this is a worsening threat to wild plants and flowers, many facing extinction.
The authors identify managed honeybees and their honey production and pollination of commercial crops as an agricultural issue, not an ecological one. They advocate restriction of managed honey beehives in protected-ecological areas to reduce their harmful effects noting that half of all European wild bees are threatened with extinction.
Once upon a time, millions of rhinos roamed across Africa and Asia; now about 30,000 survive, and many species are extinct or about to be. Sudan, the last male northern white rhino lived at Ol Pejeta Conservancy in Kenya together with his daughter Najin and granddaughter Fatu. He was 45, equivalent to 90 in human age, and quite infirm. Earlier this year, when his condition deteriorated to the extent he was unable to stand, the vets decided to euthanize. Hope lies with in vitro fertilization, and in the genetic material the vets collected from him. At some future date, it might be possibly to use this to create an embryo with stem cell technology.
The engaging, lovable and cuddly koala is in danger from environmental effects. its unusual diet of eucalyptus leaves carry a toxin it can usually handle, but increased CO2 levels reduce nutrition and eating more leads to ingesting more poison. Add to this the Australian drought drying the leaves, leaving little moisture and resulting in kidney damage.
Altogether, these studies and cases convey a stark warning. They show that environmental degradation is the promise of a dismal future in which mammalian wildlife is scarce, wild pollinators and consequently wild flowers and plants are sparse, and beautiful coral reefs succumb to plastic waste-borne bacteria depleting reef-supported fisheries. This is our legacy unless we take a step back to reassess human wants for their impact on the environment.