The Impact of Climate Change on Rivers

Rivers provide life and sustenance to humans, plants and animals and they were our very first highways before roads were made. There are 165 major rivers on planet earth, mostly flowing south with the exception of four of the longest rivers that flow north.

Our rivers are the first areas to be heavily impacted by climate change. Rising temperatures, frequent extreme storms and changes in season precipitation rates are finally taking their toll. We have to remember that climate change equals water change.

River communities are seeing increased flooding, droughts and waterborne diseases which are all having extreme impacts on their daily lives. Our drinking water comes directly or indirectly from streams and rivers. It, therefore, makes sense that when our rivers and streams become polluted, so does our drinking water.
Read our blog on Dangerous Pathogens found in Rivers

To put it mildly, the future does not look good unless we take drastic action.

Rising temperatures in rivers affect aquatic life

Aquatic species all have a preferred temperature range in which they live, and when this range is affected, this can cause the death of species that cannot live in warmer waters. Moreover, a rise in water temperature also affects water chemistry.

Groundwater, for example, can have a higher electrical conductivity as the higher water temperature dissolves more minerals from the surrounding rocks. Warm water holds less dissolved oxygen than cold water, which means there is ultimately less oxygen for aquatic life. Certain water compounds also become more toxic once temperatures rise.

Let’s take trout or salmon, for example. These fish are cold-water species and therefore require cold water for their very survival. If our river temperatures keep rising, these fish will be replaced by species able to live in warmer waters and trout and salmon meals will become a thing of the past.

Why Algal blooms can be deadly

If our river temperatures keep rising we risk excessive algal blooms which are very harmful to aquatic life, humans and our global economy. In order to maintain water quality, we have to reduce excess nutrient pollution. So when rising water temperatures and excess nutrients such as phosphorus and nitrogen enter the rivers and lakes, we see algal blooms. When this happens it reduces the amount of oxygen available to aquatic life, causing dead zones where no life can flourish.

Not only do algal blooms affect aquatic life, but the water quality also becomes severely affected resulting in unsafe drinking water that requires costly additional water treatment. It becomes a vicious loop.

Read our blog on Reducing harmful algal blooms

Drinking water will become costly

With more frequent storms come heavier rainfall, which in turn causes pollutant runoff and sedimentation in our rivers and lakes. This complicates treatment in source waters and pushes up the costs of treating drinking water. Ultimately it is the consumer who bears this cost, which means that drinking water will become very expensive.

We can expect more droughts as climate change increases. Less rainfall means less drinking water.

Rising sea levels are also inviting more saltwater intrusion into our lakes and rivers, affecting the availability and quality of source water.

What is the solution?

Protecting and restoring rivers must be part of the global solution along with decreasing global warming pollution. There are many wonderful river restoration projects across the globe that focus on protecting rivers. Grasses, shrubs and trees are planted along the stream and river banks to create a buffer. Buffers improve water quality by filtering pollutants and sediments from soil runoff and they also help to keep the water cool by providing necessary shade.

Moving Water Alliance is an organisation that supports beach and river cleanup organisations and encourages riverbank restoration projects across the globe.

We can each do our part, it’s not difficult. It just requires a few minor adjustments to your lifestyle.

4 things we can do to help:
  1.  Use only environmentally-friendly cleaning products in your home as whatever you flush down your drain ends up back in the rivers.
  2. Preserver water by using it sparingly. That means you need to turn off your tap while you’re brushing your teeth and be sure to only use your washing machine when you can do a full load.  You should also consider timing your shower time as a 10-minute shower uses roughly 25 – 50 gallons of water, depending on your shower head flow. You can also consider catching water from your shower in a large bucket while you wait for the water to heat. This water can then be used to water your plants or flush your toilet. You could also consider installing a low-flow shower head to help you save more water.
  3. Since energy production requires water to cool power plants, it makes sense to turn off appliances and lights when not in use to save electricity and the water used for the cooling process.
  4. Since so much plastic ends up in our rivers, it also makes sense to avoid single-use plastic.  Take your own fabric shopping bags along when you buy groceries, and your own coffee mug when you buy takeout coffee. Eliminate plastic straws from your life and buy environmentally-friendly bamboo straws instead. Learn how to recycle properly so that your plastic doesn’t end up in our rivers.

Want to know how much water your household uses? Use this handy Water Calculator.

If we don’t take drastic action now, not only will we end up with heavily polluted rivers and reduced aquatic life, but we will suffer severe water scarcity which means many of our citizens will die. As it stands, 1.1 billion people currently lack access to water and a total of 2.7 billion find water scarce for at least one month of the year, according to WWF.

So next time you brush your teeth whilst leaving the tap running, think about how you will access clean and safe drinking water ten years from now.

How seaweed is changing the world

As climate change continues to exacerbate ecological challenges and considerably decreases the areas of agricultural land available, the global demand for nutrients will increase drastically. More and more, we will look to the oceans for our very survival.

Take seaweed, for example. For centuries humans have consumed seaweed in one form or another. Seaweeds are fast-growing algae with many beneficial uses to both marine life and humans. Through the process of photosynthesis, seaweeds convert sunlight into energy and take up nutrients and carbon dioxide from the oceans. While rain forests only produce 28 percent of the oxygen we breathe, seaweed, kelp, phytoplankton, and algae plankton produce 70% of the oxygen we breathe.

Would you believe that seaweed is actually the ancestor of everything that grows on planet earth? Paleontologists recently announced the discovery of a billion-year-old seaweed fossil in northern China. Some scientists firmly believe that all the trees and plants we have today originated from seaweeds.

With resources on our planet steadily decreasing, it’s no surprise then that humans have turned to seaweed for ongoing food and medicinal help.

Seaweed can be found in many everyday products. From cosmetics to medicine, pet food, and even toothpaste. Recently they’re also used in biodegradable packaging, textiles, and even straws.

In 2019, the global seaweed business was estimated to be worth US$13.33 billion, with projections of that number reaching US$23.04 billion by 2027. Mostly farmed in Asia, inland seaweed farming outside of Asia has taken off in recent years.

Sustainable seaweed farming

The food industry’s interest in sustainable additives and food security grows each day, driven by a hungry population who are becoming increasingly concerned about the environment and the negative consequences of consumerism.

Seaweed farming began around 1670 in Japan and is now practiced all over the world.

While China, Indonesia, and the Philippines still produce most of the edible seaweed products on the market, seaweed farms are popping up all over the globe.

One such operation, AlgaPlus has a series of ponds and tanks in Northern Portugal where they cultivate seaweed in a much more controlled environment than that of traditional ocean seaweed farms. Their production includes the only European commercial-scale hatchery of the species Porphyra spp., also known as Atlantic nori.

Seawater from a coastal lagoon flows into the fish ponds at AlgaPlus, where it’s pumped through a filtration system into tanks that grow the seaweed. The advantage of this method of farming is additives or fertilizers are not needed, as the seaweed is nourished by the water from the fish in their ponds, making it a highly sustainable operation.

In another part of the world, seaweed farming is proving to be a very important resource for women. Tanzania is an East African country and home to the Serengeti National Park. It might surprise you to know that seaweed farming is considered the third biggest contributor of foreign currency to the country, where 90 percent of seaweed farmers are women. In their shallow-water farms, they wait 45 days for their seaweeds to grow, then pick, dry, and package their seaweeds to be exported to countries like China, Korea, and Vietnam. But due to climate change, farmer numbers have dwindled over the past few decades.

At one point there were over 450 seaweed farmers in Tanzania. Now there are only about 150. But thanks to a program run by The Nature Conservancy, farmers are now being educated about how to improve their farming operations in the hopes of increasing the number of farmers in the region.

Common seaweed strains for consumption

While mainly consumed in Asian countries, seaweed products are starting to enjoy popularity around the world. Global seaweed aquaculture production now occupies about 20 percent of the total world marine aquaculture production by weight. Seaweed aquaculture production is dominated by relatively few species namely the brown kelps and the red seaweeds.

Different seaweeds / kelp

Pyropia is a genus of red alga found around the world in intertidal zones and shallow water and commonly used to make “nori” – a dried edible seaweed used in Japanese cuisine and often used to wrap rolls of sushi or onigiri. It has the highest commercial value per unit mass at $523 per wet metric ton. (In case you are wondering why nori is green but made from red alga, when added to boiling water (100 degrees C) the other pigments in the seaweed melt and dissolve leaving behind the bright green chlorophyll).

Kelps are large brown algae seaweeds that grow in underwater forests in shallow oceans. Along the Norwegian coast, these forests cover 5800 km2, and they support large numbers of marine animals. Kelp fetches $141 per wet ton.

Gracilaria (red algae) are found in warm waters throughout the world, though they also occur seasonally in temperate waters and cannot tolerate temperatures below 10 degrees C. Gracilaria fetches $273 per wet ton.

Kappaphycus is a genus of red algae with species distributed in the waters of East Africa, Malaysia, Indonesia, the Philippines, Micronesia, and Hainan Island. Kappaphycus fetches $172 per wet ton.

Sargassum is a genus of large brown seaweed that floats in island-like masses, never attaching to the seafloor. They can be found in shallow waters and coral reefs.  Sargassum fetches $460 per wet ton.

Read our blog: Why we need to tackle our sargassum issue

How seaweed farming can help combat climate change

Considered a carbon-negative crop, seaweed also has a high potential for climate change mitigation. Furthermore, seaweeds can grow extremely quickly, about thirty times faster than land-based plants. Indeed, nothing on earth sequesters carbon faster than giant kelp which can grow up to 60 meters in length and as fast as 50 cm per day under the right conditions.

The University of the South Pacific published an analysis as early as 2012 that revealed exactly how seaweed farming could help to combat climate change. Their analysis revealed that if 9% of the ocean were to be covered in seaweed farms, the farmed seaweed could produce 12 gigatonnes per year of bio digested methane. This methane could be burned as a substitute for natural gas. Even at smaller scales, seaweed farming has the potential to substantially lower atmospheric CO₂.

Seaweed in the food chain

Seaweed isn’t just eaten in sushi bars. Many of the foods we consume every day employ thickening agents to make them more palatable and easier to scoop. Several strains of red algae provide natural gels that bind food such as Agars, Alginates, and Carrageenans. Some of the products include desserts, chewing gum, jellies, jams, dairy products, salad dressings, candies, ice creams, jellies, beers, and wines.

Seaweed for the garden

Seaweed can also be applied whole to garden soil. You can also buy seaweed that is dried and ground for fertilizer.  Or you can buy seaweed that is processed and made into seaweed extract, which is then diluted for use. Seaweed fertilizer adds trace elements as well as plant nutrients like potassium, nitrogen, and phosphorus to the soil.

Furthermore, whole or dried seaweed also adds organic matter to the garden. Considering how toxic regular commercial fertilizers are for the delicate ocean ecosystems, seaweed fertilizers are a much safer option.

Seaweed for building houses

Probably the best use being given to seaweed in the Caribbean is in building houses. Sargassum bricks are made with the same technique as adobe bricks. The use of this seaweed can reduce the total cost of building homes by up to 50%, making it perfect for low-income families or sustainable buildings.

Other uses for seaweed

Uses for seaweed are virtually endless. They are used to make cardboard, paper, and even textiles. Seaweed is also used in pharmaceuticals as binders, stabilizers, emulsifiers, and for creating molds. Even the dental industry uses them in molding preparations. Hair strengthening treatments, as well as makeup, moisturizing creams and sunscreens are some of the products that are being produced with seaweed.

Read our blog: is your sunscreen harming the ocean?

Furthermore, methane emissions could be cut by 90 percent if livestock were fed on seaweed-based foodstuffs, rather than soy. It would also improve digestion whilst boosting the animals’ immune systems, thereby reducing the need for antibiotics.

Seaweed as a first choice

Not only does seaweed pose a solution to food scarcity and climate change, but it’s helping us to create biodegradable products. Next time you’re out shopping, reach for the products made from seaweed first. You’ll be doing the environment a ton of good