State of the world - what has happened in 25 years

Lauantai 18.11.2017 klo 12:40 - Mikko Nikinmaa

Twenty five years ago the Union of Concerned Scientists wrote "World Scientists' Warning to Humanity" (with the major authors and 1700 scientists' signatures) where they were concerned about population growth, freshwater availability, climate change, extinctions etc. Now, scientists have looked at what has happened in the past 25 years, and concluded that "World Scientists' Warning to Humanity: Second Notice" was in order. This article was published on November 13 in Bioscience with William J. Ripple as the first author (in addition to the major authors the article had 15,364 scientist signatories from 184 countries). Apart from the ozone hole, which is now starting to shrink, all the environmental problems recognized in 1992 have become worse, and are still continuing to be more detrimental. For example, the amount of carbon dioxide emissions has increased in the last year after it had stabilized or even slightly decreased in the previous two years. In the past 25 years, the availability of fresh water has decreased by 25 %, mean global temperature increased by 0.5 degrees C, carbon dioxide emissions have almost doubled, the dead zones in marine areas increased by almost a third, forests decreased by about 5 % and vertebrate species number decreased by about 30 %. Although human population growth has stopped in the developed countries, the same thing has not happened in Africa and most Asian countries, whereby the total world population has increased by almost 40 % with no sign of increase rate to be slowing down. The number of extinctions in vertebrates is probably much smaller than that of invertebrates - for example insect biomass in certain protected areas in Germany has decreased by 75 %. A significant problem is also that despite increased catching effort, the marine fish catches have decreased by about 20 % from the best years. One final note of the gloomy statistics, we consider almost always only deforestration as causing a decrease in carbon dioxide removal. However, because of the prevalence of sea area, almost half of global photosynthetic activity takes place in marine algae. Marine pollution has decreased algal photosynthesis by approximately 10 % in the past 25 years.                                

Although most of the indices show radical worsening in the state of global environment, the situation with ozone hole indicates that if mankind heeds the warnings, we are able to make the changes required to keep the environment in satisfactory state. The stratospheric ozone layer above Antarctica is now strongest since 1988. If similar united actions were done for the other questions pinpointed by the authors of the Bioscience article, they could also be solved in reasonable fashion. Changes of diet, schooling, improvement of women's situation, discontinuation of fossil fuel use could all be done if we so decided.

Kommentoi kirjoitusta. Avainsanat: deforestration, population growth, fisheries, climate change, extinctions

Fishing quotas - strict ones are needed to protect fish

Torstai 20.7.2017 klo 13:53 - Mikko Nikinmaa

Fishermen always complain that they are allowed to fish too little and fish biologists have alerted people to the fact that politically decided fishing quotas are too big. If fishing cannot be reduced, several preferred species will become extinct in the next hundred years. The lobbying groups for fishing industry have hitherto been able to convince politicians that putting money in new and effective fishing vessels and having fishing quotas enabling overfishing are good ways of preserving employment - one need not care if preferred fish disappear from nearby areas. With new vessels obtained, e.g. with European Union support, one can have longer fishing journeys than earlier.

It appears that a significant problem with fishing is that the identification of fish by fishermen is poor. If one is approaching the maximum allowed quota for one species, the fish are just marked to be of species, where quotas are not near filling. Giving this type of misinformation varies a lot depending on which country the fisherman is from.

However, even in the interests of fishermen, the fishing quotas should be set on scientific, and not political grounds. Further, the quotas should be followed. And actually, increasing the use of aquacultured fish with land-based feed and effective removal of wastes, is the way forward. All these points are important in order to have fish diversity also for future generations.

Kommentoi kirjoitusta. Avainsanat: fisheries, biodiversity, marine protection

Blue Economies - The Seas Affect Our Lives in Many Ways

Keskiviikko 14.6.2017 klo 10:21 - Mikko Nikinmaa

Blue economies are another recent catchword, which indicates economical activity associated mainly with marine environments. From the environmental point of view there are a couple of things that need to be realized.

First, marine pollution is a huge problem. It is probably the biggest single factor behind climate change. Because of the large sea area, algae, largely unicellular microalgae, contribute 40-50 % of the total photosynthesis of the earth. Although in certain areas microalgal growth has increased, it has been estimated that owing to marine pollution the overall amount of carbon dioxide fixed by algae has decreased 10-20 %. This decrease of carbon dioxide sink is greater than that caused by recent rainforest cuts. An important component of marine pollution which has recently got much attention is plastic pollution. A lot has been talked about microplastics, but the weathering of plastics generates even smaller components, nanoplastics, which affect phyto and zooplankton. Their effects can be direct, but additionally they can result in hydrophobic environmental pollutants to become concentrated and available to organisms.

Second, world's seas are overfished. Environmentally, the use of cultured fish would be better than supporting fishing that can cause extinction of the most popular food species within 100 years. However, the problems with aquaculture are the present marked use of antibiotics and pesticides. Both should be diminished. Also, at present the feed is mainly fish flour, which means that overexploitation of natural fish is not reduced by aquaculturing, only changed to species with less human consumption. So, environmentally friendly aquaculture would require development of feeds that are not based on fish flour.

These are two things that need to be considered when developing blue economies. 

Kommentoi kirjoitusta. Avainsanat: climate change, marine pollution, microplastics, fisheries