Where have the eels gone

Keskiviikko 18.1.2023 klo 14:51 - Mikko Nikinmaa

Everything was better in the past. That is the slogan of conservative populists throughout the world. It is actually true for some things, but the actions should be completely different from the ones advocated by the populists in order for us getting the good things from the past also in the future.

Here I am focussing on the eel. Smoked eel is a true delicacy. When I was a child, one got eels virtually every time one went fishing. The fish was fatty and had virtually no bones making it tasty and easy to eat. However, eels started disappearing from the shops and waters from 1970’s onwards and now you can rarely find them anywhere.

The life cycle of the eel is the main reason why the species is so vulnerable to environmental contamination. The European eel stocks have decreased more than 90 % from 1970’s to 2010’s. If one starts from the sexually mature eel, it migrates several thousand kilometres from the inland waters, where it matures, to the spawning site in Sargasso Sea. During this months-long migration the fish does not eat, but uses the fat deposits as energy stores. This fact has several consequences. First, the condition of eels reaching the spawning site is poor. Many do not make it to the site at all, and the rest are barely able to make the final effort of the spawning migration. Any lipid-soluble environmental contaminants are released to the circulation when lipid deposits are used for energy production. This further weakens the fish. Also, because of the climate change, the ocean currents may have weakened causing an increase in the energy consumption during swimming from Europe to Sargasso Sea. This also weakens the eel before spawning.

The adult eels die after spawning, but the developed embryos start their long travel towards the European feeding grounds. No specific problems have been found in the early part of the migration in the Atlantic. However, it is possible that the food items of the eel embryos have decreased in abundance and that ocean currents have slowed down. When the eels come to the European coasts, a final strenuous part of the travel awaits. They must go up to suitable growth sites. In selecting where to swim to, eels use, e.g., the lateral line organ. This sensory organ is very sensitive to metal contamination. Thus, the present increases of copper, lead and cadmium levels may disturb the final leg of eel migration.

In short, eels suffer from environmental contamination in most parts of their migration. Further, the studies have shown that the presently occurring contaminant levels are adequate to cause, e.g., sensory problems. Consequently, to be able to go back to the good old days, when smoked eel was a common delicacy, we need to improve water quality.

Kommentoi kirjoitusta. Avainsanat: aquatic toxicology, metal pollution, climate change

Lead Poisoning - a Problem Especially for Children in Poor Areas

Perjantai 31.7.2020 klo 16:55 - Mikko Nikinmaa

The first large-scale lead poisoning dates back to Roman times. Many historians are of the opinion that the downfall of Roman empire was partly due to large-scale lead poisoning. The drinking water was lead to Rome and some other big cities in lead aquaducts, with the consequence that some lead dissolved in water and was drunk. The amount of lead this obtained was enough to cause neurotoxicity.

The second time that concerns of common lead poisoning reached news was when car traffic using leaded fuel increased markedly in industrialized countries. This led to quite rapid phasing-out of lead in petrol in 1989’s. Lead was also an important component of paints in, e.g. kitchenware and toys, whereby everyone but especially children were exposed to toxic lead concentrations. Because of this, also lead-containing paints have been banned. As a result of the bans of lead in fuels and paints the lead levels in the blood of children in industrialized, rich countries has decreased to values which do not cause observable toxicity.

The toxicity of lead is especially harmful to children. Lead is primarily a neurotoxicant. It disturbs brain development. If brain development of a child is disturbed, the disturbance persists for the rest of the life. Lead-poisoning decreases the intelligence, increases aggressiveness and generally makes the affected people lethargic. It also decreases the attention time span; it has been estimated that a quarter of ADHD cases would, in fact, be caused by lead poisoning. There are also associations between lead poisoning an hearing acuity, which suggests that lead exposure may cause speech and language handicaps.

Above the level of 5 micrograms per decilitre (µg/dL), lead causes theIMG_20170813_01802.jpg intelligence, behaviour and learning problems as estimated by the American CDC (Center of Disease Control and Prevention) and WHO (World Health Organization), although WHO points out that there is no safe level of exposure. If the 5 µg/dL concentration is taken as the limit, a third of world’s children have exposure, which causes life-long effects. As children in industrialized countries do not normally have these high lead levels in their blood, this  is another problem between poor and rich countries.

We in industrialized countries have become aware that resources, such as metals, should be recycled. If this is done responsibly, it helps a lot for making the resource use in the world sustainable. However, many of the recycling companies are not in the business to help the earth but to make money. As a result, the “recycling” is done in poor countries, and no precautions, which would be required in Europe and North America, are followed. Because of this, recycling lead-acid car batteries has become the single most important source of lead exposure for children in poor countries. Thus, one should demand that recycling must be done in the commercial area, where the product is used. In addition to car batteries, lead-containing paints and toys containing lead are still common in poor areas.

A more detailed account of lead problem in children is the report by UNICEF and Pure Earth:  The Toxic Truth: Children’s Exposure to Lead Pollution Undermines a Generation of Future Potential, which is available at https://www.unicef.org/reports/toxic-truth-childrens-exposure-to-lead-pollution-2020


Kommentoi kirjoitusta. Avainsanat: metal pollution, lead exposure, car batteries, sustainability

Coronavirus pandemic signifies the end for greedy globalism but should be the starting point for sustainable globalism

Sunnuntai 10.5.2020 klo 17:35 - Mikko Nikinmaa

Looking at the figures showing, how coronavirus is spreading in the world, one cannot but come to one conclusion. The situation is rapidly becoming worst in countries with populistic leaders who preach nationalism. Also, most indicators of world’s present problems show that the greedy economic globalism has failed miserably, and is contributing to the possible rise of next pandemic, climate change, immigration and environmental pollution.

On the other hand, the coronavirus pandemic has shown that the world is one entity, regardless if we want it or not. Currently the virus has spread to 212 countries, and the fact that one can travel from the most remote part of the world to any centre means that the only way to avoid the spreading of this or future pests is complete isolation from the rest of the world. From this I can reach only one conclusion: the only way to have acceptable future is to start sustainable globalism.

A starting point for sustainable globalism is that human population growth must be stopped, and should actually start to decrease. This is already happening in several rich countries, but it is invariably presented as a huge problem threatening the future of the nations concerned. The population growth mainly occurs in poor nations, which were for a long time under colonial rule. Because of this, any efforts originating from the industrialized countries to curb population growth are easily viewed as tries to re-establish colonial rule. As long as the efforts are seen as the rich countries’ effort to maintain their wealth, this is an unavoidable conclusion. Thus, curbing population growth cannot succeed, if nationalistic attitude prevails: it requires understanding that it is needed for global health. Consequently, the global wealth inequality should be decreased.

Decreasing wealth inequality is largely correcting colonial injustices, which persist even today. One cannot say that the currently poor areas like Africa would be poor because of their lack of natural resources. They are poor, because the resources are not used for their benefit, but profit usually multinational companies based in rich countries. This is also true for both manufacturing and agricultural production. With regard to agricultural production, poor countries often cultivate plants which are exported to rich countIMG_20170807_0157.jpgries and do not feed the local population. Furthermore, the production is largely owned by companies residing in rich countries. When agricultural production is largely exported, the poor countries end up as importers of food required by the local people. With regard to industrial production, much of it is done for export. Again, the companies are largely parts of multinational ones with headquarters in rich countries. The reasons for production in poor countries is first that the salaries are very low, but also that environmental standards required for production in rich countries need not be followed whereby production costs are minimized. This type of cutting cost is the greedy economic globalism, which the true sustainable globalism should do its utmost to fight against. The solution to decreasing wealth inequality is actually quite simple. All the products from poor areas are priced as if they were produced in rich countries, and the difference in the present and future price is given to (especially women’s) education, improving the environmental standards of production and salaries. The funds cannot be given directly to the governments of the poor nations, because they are (unfortunately) often corrupt, and would just use the funds for their own benefit instead of using them for the benefit of the people.

The third part of changes, which are required in order to combat one of the grave problems, the climate change, is to stop using fossil fuels. I don’t go further in detail to it, because the two directions above will immensely help in achieving that goal, and because there are already several technological possibilities for the required change.

Why should we then do all of this? The answer is really simple: I suppose we want our children and grandchildren to be able to live in an open society. If this is our hope, we must be able to decrease the likelihood of viral transmissions from animals to humans. They have increased in frequency in recent years, because increased human population decreases the space available for animals, and consequently animal-human interactions increase. Vegetarian diet is not a solution, because direct animal-human transmissions remain a possibility. In addition to avoiding zoonosis, sustainable globalism would also decrease migrations and environmental pollution and combat climate change.  

Kommentoi kirjoitusta. Avainsanat: climate change, migration, population growth, economic growth, wealth inequality, environmetal pollution

Physiological studies clarify how copper pollution and hypoxia affect fish

Tiistai 21.1.2020 klo 17:17 - Mikko Nikinmaa

Two major problems in the oceans are the spreading of hypoxic areas (areas with low oxygen level) and copper pollution. The ocean deoxygenation problem is the subject of an IUCN report, downloadable from https://www.iucn.org/resources/publications, and it has been discussed also in this blog on December 13, 2019 (Deoxygenation of oceans is an increasing problem with effects on sealife). Copper pollution is caused especially because copper is a component of antifouling paints of ship hulls and boats. These paints are used to kill all organisms attaching on boats (discussed in this blog, Environmental Effects of Shipping, January 15, 2020). These two problems interact. Exposure to copper decreases tolerance to low oxygen level in fish. This is possibly due to copper causing thickening of gill epithelium, whereby oxygen transfer across the epithelium is decreased. In contrast, previous hypoxia reduces tha effects of copper on fish. This is probably due to copper effects being reduced after hypoxia-inducible factor (HIF)-dependent pathway is activated.

Several studies on copper-hypoxia interactions on the functions of fish have been published from 2004 onwards (e.g. van Heerden et al. Aquatic Toxicology 69, 271-280, 2004; Fitzgerald et al Aquatic Toxicology 217, 105325, 2019; Zeng et al. Science of the Total Environment 708, 134961, 2020). They indicate how important physiological studies are for understanding, how humans affect the ocean ecosystems.  

Kommentoi kirjoitusta. Avainsanat: climate change, ocean acidification, metal pollution

Ban Fireworks

Sunnuntai 30.12.2018 klo 9:21 - Mikko Nikinmaa

It is again time that billions of euros are burned. Thrown away in skies to have fine fireworks. There is probably no more unnecessary consumption than fireworks in new year's eve. One could compare it to lighting up and burning money - except that burning money as such would be much less harmful than fireworks. All the colours that the fireworks give out are the colours of burning metal ions - and many metal ions are quite poisonous. In fact, many people who complain about metal pollution from mines are ready to pollute their imIlotulitus.jpgmediate surroundings with poisonous metals.In adddition to the poisonous metals themselves, the empty firework trash fills the surroundings.

Then the noise. We had a dog, whom it was impossible to get out between the time that shooting fireworks starts and the time it finished. At home it always  tried to find a place, where there was least noise. It is quite common that dogs and other pets are really scared of the noide. In the media there are every year columns giving advice to people with fireworks-scared pets. Avoiding this problem would be simple. Ban fireworks. 

In addition to causing metal and noise pollution and trash, accidents with fireworks cause a high amount of medical cost with some peopple becoming permanently blind. Further, sustainability can only be reached, if unnecessary consumption is stopped. And if anything, shooting fireworks is unnecessary consumption. Since there are several negative points, and only one supporting one - fireworks look pretty, they should be banned. In Finland, people's petition at kanslaisaloite.fi has reached an adequate number of signatures so that the fireworks ban must be taken up in the parliament. I hope it is successful

Kommentoi kirjoitusta. Avainsanat: metal pollution, noise, consumption