Tag Archives: biodiversity loss oceans

Natural Capital and Human Well-Being

What is the contribution of nature to the economy?… The breathable air, drinkable water and tolerable temperatures that allow humans to do everything they do, and the complex ecosystems that maintain them, tend to be taken for granted. Professor Dasgupta’s review on the Economics of Biodiversity does not seek to play on the heartstrings with tales of starving polar bears. Rather, it makes the hard-headed case that services provided by nature are an indispensable input to economic activity. Some of these services are relatively easy to discern: fish stocks, say, in the open ocean. Others are far less visible: such as the complex ecosystems within soil that recycle nutrients, purify water and absorb atmospheric carbon. These are unfamiliar topics for economists, so the review seeks to provide a “grammar” through which they can be analysed.

The report features its own illustrative production function, which includes nature. The environment appears once as a source of flows of extractable resources (like fish or timber). But it also shows up more broadly as a stock of “natural” capital. The inclusion of natural capital enables an analysis of the sustainability of current rates of economic growth. As people produce GDP, they extract resources from nature and dump waste back into it. If this extraction and dumping exceeds nature’s capacity to repair itself, the stock of natural capital shrinks and with it the flow of valuable environmental services. Between 1992 and 2014, according to a report published by the UN, the value of produced capital (such as machines and buildings) roughly doubled and that of human capital (workers and their skills) rose by 13%, while the estimated value of natural capital declined by nearly 40%. The demands humans currently place on nature, in terms of resource extraction and the dumping of harmful waste, are roughly equivalent to the sustainable output of 1.6 Earths (of which, alas, there is only the one)…Indeed, Professor Dasgupta argues that economists should acknowledge that there are in fact limits to growth. As the efficiency with which we make use of Earth’s finite bounty is bounded (by the laws of physics), there is necessarily some maximum sustainable level of GDP…

Professor Dasgupta hints at this problem by appealing to the “sacredness” of nature, in addition to his mathematical models and analytical arguments.

Excerpts from How should economists think about biodiversity?, Economist, Feb. 6, 2021

Mining the Ocean: the Fate of Sea Pangolin

A snail that lives near hydrothermal vents on the ocean floor east of Madagascar has become the first deep-sea animal to be declared endangered because of the threat of mining.  The International Union for Conservation of Nature (IUCN) added the scaly-foot snail (Chrysomallon squamiferum) to its Red List of endangered species on 18 July, 2019 — amid a rush of companies applying for exploratory mining licenses…. The scaly-foot snail is found at only three hydrothermal vents in the Indian Ocean.  Two of those three vents are currently under mining exploration licences,…Even one exploratory mining foray into this habitat could destroy a population of these snails by damaging the vents or smothering the animals under clouds of sediment..

Full-scale mining of the deep seabed can’t begin in international waters until the International Seabed Authority (ISA) — a United Nations agency tasked with regulating sea-bed mining — finalizes a code of conduct, which it hopes to do by 2020….The biggest challenge to determining whether the scaly-foot snail warranted inclusion on the Red List was figuring out how to assess the extinction risk for animals that live in one of the weirdest habitats on Earth…

When the IUCN considers whether to include an organism on the Red List, researchers examine several factors that could contribute to its extinction. They include the size of a species’ range and how fragmented its habitat is…The IUCN settled on two criteria to assess the extinction risk for deep-sea species: the number of vents where they’re found, and the threat of mining.   In addition to the scaly-foot snail, the researchers are assessing at least 14 more hydrothermal vent species for possible inclusion on the Red List.

Excerpts from Ocean Snail is First Animal to be Officially Endangered by Deep-Sea Mining, Nature, July 22, 2019

On Sea Pangolins see YouTube video

The Super-Corals

By some estimates, half of the world’s coral has been lost since the 1980s. Corals are delicate animals, and are succumbing to pollution and sediment from coastal construction. Also to blame are sewage, farmland run-off and fishing, all of which favour the growth of the big, fleshy algae that are corals’ main competitors for space. (The first two encourage algal growth and the third removes animals that eat those algae.) But the biggest killer is warming seawater. Ocean heatwaves in 2015, 2016 and 2017 finished off an astonishing 20% of the coral on Earth. This is troubling, for countless critters depend on coral reefs for their survival. Indeed, such reefs, which take up just a thousandth of the ocean floor, are home, for at least part of their life cycles, to a quarter of marine species. Losing those reefs would cause huge disruption to the ocean’s ecosystem. So researchers are looking for ways to stop this happening.

A growing number of scientists reckon that an entirely different approach to saving coral is needed. If oceans are changing faster than coral can adapt via the normal processes of evolution, why not, these researchers argue, work out ways to speed up such evolution  One way to do this would be selective breeding. Most species of coral spawn on just one or two nights a year, a process regulated by the lunar cycle, the time of sunset and the temperature of the water. The sperm and eggs released during spawning meet and unite, and the results grow into larvae that search for places where they can settle down and metamorphose into the stone-encased sea-anemone-like polyps that are the adult form. In the wild, the meeting of sperm and egg is random. Some researchers, however, are trying to load the dice. By starting with wild specimens that have survived a period of heat which killed their neighbours, they hope to breed heat resistance into the offspring.

This is the tack taken, for example, by Christian Voolstra of the Red Sea Research Centre in Thuwal, Saudi Arabia. He describes it as “making sure super papa and super mama meet and reproduce”. Corals bred in this way at the Hawaii Institute of Marine Biology, on Oahu, survive in water that is warm enough to kill offspring resulting from normal, random reproduction.

The reason corals die when the surrounding water gets too hot is that the microscopic algae and bacteria which live on and in their tissue, and are their main food sources, are sensitive to small changes in temperature. When stressed by heat these symbionts start producing dangerous oxidants. This causes the polyps to eject them, to ensure short-term survival. The reef thus turns ghostly white—a process called bleaching. Bleached coral is not dead. But unless the temperature then drops, the polyps will not readmit the algae and bacteria, and so, eventually, they do die.

Polyps that survive one such ordeal will, however, fare better if temperatures rise again. The second time around they have acclimatised to the change. Some species, indeed, can pass this resilience on to their offspring by a process called intergenerational epigenesis. The Hawaii Institute’s efforts to develop hardier corals thus include administering a near-death experience to them. Ruth Gates, the institute’s director, says the goal is to create reefs “designed to withstand the future”. The institute’s first such reef will probably be grown inside Biosphere 2, an enclosed ecosystem run by the University of Arizona.

Another approach, taken by the Australian Institute of Marine Science (AIMS) in Queensland, is to crossbreed corals from different places, to create hybrid vigour. The results of such crosses are unpredictable, but some survive heat greater than either of their parents could cope with.

The artificial breeding of corals is, though, constrained by their cyclical breeding habits, so researchers at the Florida Aquarium, on Tampa Bay, are trying to speed the process up. The operators of the aquarium’s “coral ark” nursery stagger lighting and temperature patterns to fool the animals into releasing their gametes on a day of the researchers’ choosing. This also permits the co-mingling of sperm and eggs that would not normally meet, thus allowing new varieties to be created. According to Scott Graves, the aquarium’s boss, half a dozen such varieties show most promise of heat resistance, but the team is generating thousands more, “just like a seed bank”, as a backup.

A coral’s fate is tied so closely to the algae and bacteria which live in its tissues that, as Dr Gates puts it, it is best to think of the whole thing as “a consortium of organisms”. This is why scientists at AIMS are keen also to produce algae that withstand higher temperatures without releasing the oxidants that lead coral to kick them out. They are doing so using a process which Madeleine van Oppen, a researcher at the institute, calls “directed laboratory evolution”. In the past few years her team have grown more than 80 generations of algae, repeatedly culling those organisms most susceptible to heat stress and also to acidification, another curse of a world with more carbon dioxide around than previously. The resulting algae release fewer toxins and photosynthesise better in warm water than do their wild brethren..

[A]fter the trauma of bleaching, polyps do extend a preferential welcome to algae that have greater levels of heat tolerance. His team are thus now using special lights to bleach corals. Polyps “stress hardened” in this way will be planted on wild reefs in coming months…

This raises the question of whether the genomes of coral, algae and bacteria might be edited for greater robustness. According to Dr Voolstra, more than ten laboratories around the world are trying to do so. His own team has successfully inserted genetic material into about 30 larvae of a coral called Acropora millepora. Editing corals’ heat thresholds in this way is, he reckons, about five years away.

Whether they are created by selective breeding or genetic engineering, supercorals, the thinking goes, would not need to be placed on reefs in astronomical numbers… That thought, however, does not please everybody. Some object in principle to the idea of releasing human-modified creatures into the wild, or feel that amelioration of this sort is a distraction from the business of reducing carbon-dioxide emissions. Others have pragmatic concerns—that corals bred to survive warming seas might suffer handicapping trade-offs. So regulators have been cautious. The Great Barrier Reef Marine Park Authority, for example, will probably require that the hybrid organisms AIMS hopes to test in the open reef are removed before they begin spawning. …[T]he alternative, of doing nothing, is the equivalent of “ just throwing our hands up in the air and saying, ‘OK, we’re prepared now not to have coral’.” For the world’s oceans, that loss would be catastrophic.

Excerpts from Accelerating Evolution: Refreshing Reefs, Economist, Mar. 17, 2018, at 75

Turning Oceans into Muck

Oxygen is critical to the health of the planet. It affects the cycles of carbon, nitrogen and other key elements, and is a fundamental requirement for marine life from the seashore to the greatest depths of the ocean. Nevertheless, deoxygenation is worsening in the coastal and open ocean. This is mainly the result of human activities that are increasing global temperatures (CO2-induced warming) and increasing loads of nutrients from agriculture, sewage, and industrial waste, including pollution from power generation from fossil fuels and biomass.

Facts: During the past 50 years the area of low oxygen water in the open ocean has increased by 4.5 million km2. The world’ oceans are now losing approximately  1 gigaton of oxygen each year. The Millennium Ecosystem Assessment released by the UN in 2005 reported that nitrogen containing compounds (e.g. sewage, fertilizers) release into the oceans grew 80 percent from 1860 to 1990.  Increasing temperatures will reduce the capacity of the ocean to hold oxygen in the future. Oxygen deficiency is predicted to worsen in estuaries, coastal areas and oxygen minimum zones in the open ocean. The ocean’s capacity to produce oxygen will be reduced in the future.
Habitat loss is expected to worsen, leading to vertical and horizontal migration of species.

Oxygen deficiency will alter biogeochemical cycles and food webs. Lower oxygen concentrations are projected to result in a decrease in reproductive capacity and biodiversity loss. There are important local decreases of commercially important species and aquaculture production. Harmful Algal Blooms will be exacerbated from nutrients released in bottom waters due to hypoxia (e.g. in the Baltic Sea).Reduced ocean oxygen concentrations will lead to an increase in greenhouse gas emissions, thereby initiating feedbacks on climate change.

Excerpts from UNESCO, Jan. 2018

View Extensive Abstract

Background paper (pdf)

Global Ocean Oxygen Network: Through the participation of high level scientists from across the world, the IOC expert group, the Global Ocean Oxygen Network GO2NE, established in 2016, is committed to providing a global and multidisciplinary view of deoxygenation, with a focus on understanding its multiple aspects and impacts.