#which led to algal blooms which often killed off the aquatic organisms there

[dykegeology]

All this talk about ‘thirst traps‘ on ‘twitter‘... smh you’re all forgetting the real, original thirst trap... the messel pit...

[irispublishersagriculture]

Iris Publishers - World Journal of Agriculture and Soil Science (WJASS)

Soil Restoration: Drought Resistance, Soil Health Improvement, Toxin Sequestration and Worms

Authored by Leonard Sonnenschein

Land and water systems are on the verge of a collapse due to various failed schemes [1]. The ecological impact on water/land use along with dilutive residues of pesticides, herbicides, fertilizers, and over-use of soil and waterways have led to an inability for land and water systems to be sustainably managed.

The effects of climate change have further marginalized Land and Sea productivity due to change in soil and water conditions and relative cropping/water use equations [2].

Effluents from farm fields are toxifying streams and residues are being built up in adjoined waterways in the form of new eutrophic zones (dead zones); often the result of fertilizers being used to heavily increase agricultural production without consideration of the land and water ecosystem resource impact.

Discussion

The effects of agricultural runoff: nitrogen and phosphates

The agricultural sector is primarily responsible for excess nitrogen in the form of ammonia, nitrite and nitrate, phosphorus, pesticides, and pathogen pollution of water bodies in agricultural zones. Nitrogen and phosphorous are causal to eutrophication in water bodies and affecting aquatic life [3]. In maize production region of Uasin Gishu County, which is Kenya’s food basket, Ontumbi et al. [4] established that River Sosiani was stressed by nutrients (nitrates and phosphorous) originating from agricultural activities resulting in loss of biodiversity [5] and algal blooms. In Zimbabwe, Nyamangara et al. [6] reported that anthropogenic activities within the Upper Manyame Catchment Area (UMCA) were the major sources of nitrate and phosphate pollution in the three rivers and were a serious threat to the environmental sustainability of the rivers and lakes downstream. A study conducted in central Tanzania region of Singida on soils and water resources revealed that nitrate levels in water in the selected locations in Singida Urban District ranges from 105 mg/L to 476 mg/L, the values which are above the maximum recommended standard of 50 mg/L as described by WHO [7] and of 20 mg/L as per TBS [8], thus long term consumption by human beings and animals without treatment to reduce levels of nitrates may result in health problems in human and animals in the area. High levels of nitrates in water in the study area resulted from human activities particularly waste disposal, the use of natural agricultural inputs (animal manure) and crop residuals [9]. Concentration of nitrate in groundwater in many parts of Tanzania is above the background level of 10 mg/l and in some places exceeds WHO maximum recommended levels for drinking water. Highest values were observed in urban areas of Dar es Salaam, Dodoma and Tanga where the concentration of nitrate in some aquifers was higher than 400 mg/l. Generally, in urban areas, concentration of nitrate in groundwater samples decreased as one moved from densely populated areas to sparsely populated areas probably due to decreasing density of sanitation facilities. In rural settings, elevated nitrate concentration in the groundwater probably was contributed by excessive use of fertilizers (inorganic fertilizers and animal manure) [10].

Restoring plant health

Plant health can be affected by lack of either or both macro and micronutrients, disease and pests’ infestations and physiological disorders. Nutrient deficiencies can be as a result of lack or excess of nitrogen, potassium, phosphorous, magnesium or boron, copper, zinc etc. Most croplands of Tanzania have low fertility and nitrogen is the most limiting nutrient [11]. Soil phosphorus availability is commonly low. There are occasional indications of localized Cu, Zn and Mn deficiencies [12].

• Nitrogen deficiency: Low or high pH soils make the problem worse as do sandy and light soils because leaching takes place with the nutrients draining away through the soil too easily.

• Phosphorous (P): Acidic and very alkaline soils worsen the plant health. Crops with poorly developed root systems struggle without enough phosphorous.

• Potassium (K): Drought conditions and high rainfall or heavy irrigation are equally problematic when the balances of potassium are important for healthy green foliage and ensures optimal root growth.

• Magnesium (Mg): Magnesium contributes towards healthy plant development, aids with maturation process to bring forward the harvest and improves yield.

• Calcium (Ca): Calcium is important for healthy foliage and contributes to improved quality of grain and increased yields.

• Sulphur (S): S contributes to green foliage, healthy growth of the maize plant and contributes to an effective uptake of nitrogen by the crop.

• Boron (B): B is particularly important for cob and kernel development.

• Zinc (Zn): Zinc is important for good plant development early in the season and helps improve yields as well as speeds up the maturation of the plant to bring the harvest date forward.

According to Sonnenschein and Etyang [13], maize plants respond to improved soil health visually noted with increased natural moisture retention with soil becoming darker, having more worms per cubic meter of soil also indicating greater soil microbial life, with the stalks and roots being taller and thicker thus resulting in higher plant biomass in addition to doubling the cob production, pest and pathogen-free with far greater nutritional density when compared to the control plants. Clearly, micronutrients play a very important role in the life cycle of a plant.

Restoring tree productivity

Many smallholder farmers in Sub-Saharan Africa practice agroforestry. These systems have prevailed despite persistent attempts to introduce monoculture production of annual crops, which have been much less successful in Africa than elsewhere. This calls for use of low-cost option of agroforestry to replenish the lost soil nutrients. Agroforestry has been known to enhance soil fertility, improve farm income, protect water catchments, restore landscapes, conserve biodiversity and resilience against the impacts of climate change in sub Saharan Africa [14]. Soil carbon, in the form of organic matter is an indicator of soil biological activity and health. The use of diverse tree species in agroforestry systems represents alternative forms of increasing soil fertility and sustaining agricultural production [15]. Agroforestry practices have been promoted for decades both in the tropics and temperate regions of the world for their perceived benefits of not only improving soil quality, but also providing other ecosystem services [16]. Many of the environmental benefits and ecosystem services expected from agroforestry would not be materialized unless these practices improved the capacity of soils to be productive and healthy over the long term. Incorporation of trees in agroforestry enhances the Soil Organic Matter (OM) by adding litter both above and belowground. Soil OM is the energy source of soil organisms and influences both soil biodiversity and associated soil biological functions. As a result, Soil Organic Carbon (SOC) is one of the important indicators used in assessing soil health [17].

Agriculture practices affect fisheries productivity, coral reef restoration and water health

Lake Victoria in East Africa has been a recipient of both agricultural and urban waste resulting in an increase in phytoplankton, cyanobacteria, water hyacinth, and eradication of endemic cichlid fishes [3]. Mangroves at the Kenyan coast are under persistent pressure from human activities such as fish farming, manufacturing of salt, agriculture production and housing construction. Mangroves help in siltation of coral reefs and contributes to organic matter and nutrients productivity of the coastal ecosystems [18].

Cyanobacteria (blue-green algae) are photosynthetic and chemosynthetic bacteria that under favorable environmental conditions produce toxic secondary metabolites (cyanotoxins) which are harmful to the environment, including humans. Harmful cyanobacteria, or CyanoHABs, are now a problem of global environmental concern and efforts are being taken to prevent, predict, minimizes, and suppress their occurrences [19]. In nearby Lake Victoria, blooms of cyanobacteria have been observed since 1980 which are associated with massive fish kills [12]. Studies by Kihwele et al., [20] and others in the United Republic of Tanzania have demonstrated the occurrence of toxin producingcyanobacteria in specific regions.

Other indicator species such as Flamingos have shown mortality from the presence of these harmful algal blooms in Tanzania is the mass fatality of Lesser Flamingos in saline lakes in Arusha and Manyara Region [21].

In order to investigate the potential for microcystin (MC) production by cyanobacteria in the Mwanza Gulf (Lake Victoria, Tanzania), nutrients, phytoplankton and microcyst ins were sampled inshore (3m depth) and offshore (18m depth) from May to August 2002. Significant differences in soluble reactive phosphorus (SRP) and nitrate concentrations between offshore and inshore indicated eutrophication via terrestrial run-off.

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[jilliangkenny-blog]

Aquatic Biodiversity, Food Security, and Land Restoration

Blog Post 9

Chapter 11: Sustaining Aquatic Biodiversity

There are many threats to aquatic biodiversity in today’s economic and social climate. There’s still a lot to learn about aquatic biodiversity: much of the species in the deep sea have yet to be discovered by humans. While this may be true, in recent years, studies of the deep ocean have been growing. Over 2,400 scientists from over 80 different countries have began to catalog the species of the deep sea. There is still much to be discovered, but so far they have identified about 17,650 species living in the deepest ocean zone. They also add a few thousand species every single year, so this number is growing.

Many human activities are destroying aquatic habitats. To start, invasive species are a main factor in the degradation of aquatic biodiversity. Invasive species are species that do not belong in a certain ecosystem, but are introduced through movement of species. For aquatic ecosystems, this typically occurs when certain species arrive in the ballast water of ships. Certain fish and other species will get trapped in the ballast water of ships, and they are then released into foreign waters. Invasive species are so dangerous for biodiversity because they can reproduce rapidly, then consuming many other weaker native species and making them become extinct. An example of one of these invasive species is the Asian swamp eel. This eel is native to Asia, but it has invaded waters of Florida. It eats nearly anything, and it sucks up species like a vacuum. It can survive in many different environments, so it depleted many species while thriving in this foreign environment. Species like these are extremely dangerous for biodiversity, and it is hard to regulate this movement due to lack of enforcement of policies enacted by organizations like the U.N. Often times, there is no way to enforce international policies regarding habitat protection due to the lack of international law enforcement: law is primarily enforced by each sovereign state that is a part of the U.N. This limits the U.N.’s ability to implement lasting and effective policies that make a positive change regarding the protection of biodiversity.

People are also decreasing biodiversity in our oceans because of our increasing population growth. According to the U.N. Environment Programme (UNEP), approximately 80% of the world population occupies land near the coast. All the human-caused pollution in these areas, then, heavily affect the oceans. There are many different forms of pollution: plastic, toxic pollutants, nitrate fertilizers, etc. For nitrogen input specifically, this results in eutrophication of marine and freshwater systems, and this can lead to algal blooms, fish die-offs, and the degradation of ecosystem services. For plastic, those plastic items that are dumped from ships and garbage barges, as well as those left from litter on beaches, have killed up to 1 million seabirds and 100,000 mammals and sea turtles every year. All of these pollutants in total cause millions of marine animals’ lives to be threatened. There are also many fish that become entangled or poisoned by these pollutants. Overall, pollution has led to a reduction in aquatic biodiversity and a degradation of ecosystem services. Climate change and overfishing are two other causes of the decrease in aquatic biodiversity.

There are many endangered species that we do not want to live without. An example of this is the great blue whale, the largest mammal on earth. These whales are in danger because of mass whaling practices and pollution, and it is debated whether or not these species will recover. There are ways that we can protect and sustain marine biodiversity so that we do not lose some of these crucial species, like the great blue whale. There have been laws and treaties enacted to protect some endangered and threatened species. The U.S. Endangered Species Act and other international agreements have been used to pinpoint specific endangered species and protect them. Some animals protected under these agreements are whales, seals, sea lions, and sea turtles. With international agreements, though, it can be difficult to get other countries to comply, and then to enforce punishment for disobeying these agreements.

This is one of the largest issues with international policies: they can become extremely difficult to enforce. While it is a great step in the right direction to employ agreements between countries that protect ecosystem services, it may be a more important first step to get people to understand why these policies are being enacted, and why it is so important to follow them. For many within industries that are affecting aquatic biodiversity, such as fishing, working in factories, oil drilling, and others, there is not much knowledge as to why we need to act in ways that protect the environment. The only way that we can make large-scale change is if everyone that affects aquatic biodiversity is acting in a way that acknowledges the problem and constantly, on a daily basis, acts to solve the problem. If we are trying to enact policies among people who do not know or care about the issue, then it is pointless.

Something that is often used as a reference to why we need to stop polluting our oceans is the Great Pacific Garbage Patch. This is the “largest accumulation of ocean plastic in the world, and is located between Hawaii and California” (The Ocean Cleanup). The Great Pacific Garbage Patch is the perfect example of how humans have destroyed the ocean. In this huge accumulation, no life can be sustained. It has turned the ocean into a garbage can, tossing all of this plastic waste into the clean ocean and disregarding any sort of life living there. If garbage continues to accumulate in the sea like this, there will be no more aquatic biodiversity.

Planet Ocean is a very interesting documentary because it balances showing the wonder of marine life and human effects on the ocean. In the first half of the documentary, it shows fascinating marine life: coral reefs, plankton, octopi, and other animals with unique patterns of predation, camouflage, and other habits. It discusses how long the ocean has been developing and cultivating life. Then, in the second half the the documentary, it shows human processes of overfishing, offshore drilling, and factory production. They show a town in Senegal, where boats go out to fish every single day. They may be small, but they occupy the whole coast, every single day, taking thousands of fish from the ocean. If every single coastal town does this every day, it is easy to see how overfishing becomes such a huge problem. The documentary also brings light to the issue of bycatch, which is when nets catch fish that are unnecessary, or fish they do not need. These fish get tossed back into the ocean, often dead or dying, and they are killed for no reason. This is an extreme waste of ecosystem services, and it takes the lives of these animals for no reason at all. This is a huge problem with large-net fishing, and I believe it to be a moral issue that must be solved.

Chapter 12: Food, Soil, and Pest Management

Food security how accessible food is to people in a certain area. Food security is lower in areas of poverty, like in developing countries. Food production is very high, and we are currently producing enough food to feed everyone on earth; however, food waste is such a huge problem that there are many people who lack food security. This means that they have food insecurity, which means “living with chronic hunger and poor nutrition, which threatens their ability to lead healthy and productive lives” (Miller and Spoolman 278). This is a huge problem because it causes an immense amount of unnecessary suffering for so many people globally. Chronic hunger and malnutrition occurs when people do not have enough macronutrients, such as carbohydrates, proteins, and fats. They are also lacking in micronutrients, like vitamins and minerals. Malnutrition occurs when people do not have access to enough food, or when the food they do have access to is not rich in nutrients. This creates many problems, such as a lower immune system and many diseases.

This does not add up with the increased food production we have experienced over the past 100 years or so. The way humans have produced their food has dramatically shifted over the last 10,000 years. People originally would hunt and gather, but now we have huge agricultural systems that feed our world. While this is very productive to meet more people, it also takes people away from the food production process, making them more willing to waste food and ruining plant biodiversity.

There are many environmental problems associated with industrialized food production. One primary effect is topsoil erosion. This occurs when soil components move from one place to another, either by wind or by water. This can waste natural capital of land by destroying soil-holding vegetation while farming. Another main problem is drought and other human activities that are degrading drylands. Desertification is when land that was originally wet or fertile becomes desert-like due to lack of water, overgrazing or deforestation.

While there are many, many ways that the agriculture industry can ruin land, there are ways to go about solving these problems. We can reduce soil erosion by keeping land covered with vegetation instead of leaving it to waste. There are many methods of soil conservation, such as terracing, contour planting, and strip cropping. These help keep the natural capital of the land so that it is not wasted. We can also restore soil fertility by using organic fertilizer, animal manure and green manure to replenish the land.

Word Count: 1659

Question: What is the best approach to avoid problems such as overfishing? How can we balance a growing population with the problem of a lack of resources?