Don’t be shellfish – the invasive crab that isn’t too invasive
Not all invasive species are equally invasive. Sometimes, species find an opening in local ecosystems adding to local biodiversity without larger disruptions to local wildlife.
The white-fingered mud crab (Rhithropanopeus harrisii) is a small crab named after its claws that are white underneath. It is originally from the Atlantic coast of North America but has become one of the most widely spread crab species globally. It was first observed in Finnish waters in 2009 in Naantali, in southwest Finland. Since then, the crab has spread steadily and has become a common sighting all over the Archipelago Sea (figure 1).
It is said that invasive species are bad for the local environment but is it true? The jury is still out on the mud crab. The crab seems to be very successfully in adapting to different surroundings. Typically, it lives on soft, muddy bottoms but in the Archipelago Sea it has also adapted to live on rocky bottoms among the bladderwracks.
As a predator, the non-native crab could potentially affect native species drastically. The crab has adapted to feed on a variety of local species, including amphipods, mussels, and small fish. It seems to be especially fond of the Theodoxus fluviatilis, snails that clean the bladderwrack from algae. However, it looks like the presence of the white-fingered mud crab does not have any considerable effect on the populations of local species or that the bladderwrack would be affected by the diminishing of the snails.
The crab is food for others, once they get the taste for it. The cormorants, perch, and four-horned sculpins have already found the crab a tasteful addition to their diets, as indicated by stomach content studies of these species. Probably though, the crab will not end up on our plates.
The crab is here to stay whether we like it or not. It seems it has found its own niche to fill in the ecosystem of the northern Baltic Sea, finding it’s place in the food chain while not disrupting the life of the other species around it. Long term effects of the crab remain to be seen, but for now, luckily, the biggest hazard from this newcomer for locals is the possibility of being pinched in the toe when having a swim.
Camilla Arhippainen & Marcus Pellas
References:
Forsström, T., Fowler, A.E., Manninen, I., Vesakoski, O. (2015) An introduced species meets the local fauna: predatory behavior of the crab Rhithropanopeus harrisii in the Northern Baltic Sea. Biol Invasions (2015) 17:2729–2741
Fowler, A.E., Forsström, T., von Numers, M., Vesakoski, O. (2013) The North American mud crab Rhithropanopeus harrisii (Gould, 1841) in newly colonized Northern Baltic Sea: distribution and ecology. Aquatic Invasions (2013) Volume 8, Issue 1: 89–96
Havaintokartta (n.d.) https://vieraslajit.fi/havainnot?taxonId=MX.53034 Visited 1.4.2022
Puntila-Dodd, R., Loisa, O., Riipinen, K., Fowler A.E. (2019) A taste for aliens: contribution of a novel prey item to native fishes’ diet. Biol Invasions 21:2907-2917
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The Distribution and Problems of Invasive Alien Plant, Mimosa diplotricha (Mimosaceae) in Nigeria
The Distribution and Problems of the Invasive Alien Plant, Mimosa diplotricha (Mimosaceae) in Nigeria
Invasive shrubs such as Mimosa diplotricha (Mimosaceae) that impact negatively on existing plant communities pose a threat to biodiversity, agriculture, and human livelihoods. The origin of the weed is traced to Brazil, its natural habitat ranges from southern Mexico to northern Argentina including the Caribbean islands. This leguminous vine has spread throughout Asia, Africa (Nigeria, Mauritius, and Reunion).
CHARACTERISTICS AND ECOLOGY
Mimosa is one of the most diverse genera of Mimosoid legumes, with over 500 species. Central Brazil is a key center of diversity for Mimosa most farmers consider M. diplotricha to be a pest, whereas others believe it has certain advantages. They consider that soil fertility and porosity better in M. diplotricha -free areas. According to the literature, the weed is a nitrogen (N) fixer.
Problems of M. diplotricha
Agriculture, conservation, and residential areas all suffer from this pest. Infestations were found on okra, maize, cassava, and plantain farms, as well as oil palm and coconut plantations.
Assessment show that the weed is not crop specific and might be a problem in any agricultural system. This weed species has a substantial economic impact on Nigerian ago-ecosystems, burying crops and reducing agricultural growth and development.
CONCLUSION
To keep the weed from spreading and invading further Nigeria's government and institutions should share information and experiences on the management of M. diplotricha and its ecological requirements with nations afflicted by the weed, such as Australia, Papua New Guinea, India, and Thailand.
Furthermore, international collaboration and communication with nations such as Australia and Papua New Guinea that have effectively managed and controlled the weed via biological control is vital to the successful management and control of M. diplotricha in Nigeria.
REFERENCE
flickriver.com
Scirp.org
Fighting Eutrophication, one Wetland at a Time
The Västankvarn Wetland project includes the construction of two wetlands. It is a constructed Wetland built in 2019 in an area of 1.6 Ha of land. The main purpose of this project was to create a system to capture excessive nutrient runoff coming from nearby agricultural areas, from entering the coastlines in the Raseborg areas, and therefore reducing eutrophication and improving biodiversity. The project has the collaboration of multidisciplinary experts from the Bioeconomy Department of Novia UAS, Västankvarn and locals.
There were a few challenges. Pesticides represent a challenge to the wetland; they are a threat to the environment. Another problem as the sulphuric acid. The project researchers took sample of the wetland soil to check it. As a precaution, they added a few hundred tons of lime were added to the soil, to prevent the sulphuric acid to activate and be released.
This is an exciting project, and besides its benefits to eutrophication issues and the biodiversity, it will provide researchers and environmental sciences students with an excellent location to carry out their studies. The Västankvarn province is located not far from the capital city of Helsinki, making connections through roads and stations easier to visitors and researchers.
Business diversication
Doing agriculture or aquaculture farming business nowadays is demanding a sustainable and eco-friendly approach. There are a few reasons for that, mainly customers are living in the cities where is required to reduce the ecofootprint in every aspect of living. Simply customers want ecofriendly products. At the same time a sustainable approach for using resources, slowly coming into the agricultural sector and with the regulation changing understanding how to do business and take care of nature. So the pressure from both sides steps by step changes life for the better future.
Changing approach in agriculture costing a lot, new methods sometimes need new technology and but at the same time give unexpected benefits. One of the most significant benefits for farms became naturally interested from the citizens to come and check how it goes. That desire brings visitors and money with them.
Quite soon farmers realised that eco-friendly farm could also create profit from the tourists. So the answer did not take a long time. Farm and tourists clusters have appeared all over the world.
“SalmonFarm” Oy, one of the pioneers of salmon aquaculture in Finland. Located at Kimito municipality of Finland is took the wave and with the development of the main business started to develop hotel and restaurant business in the Turku archipelago.
Advantageous location, high-quality fish products, smart organization of accommodation for tourists and business became a success for the local community. It brings about 20 employees in the low season and more than triple during the summer. The local community now is more sustainable and wealthy.
But not only tourism and accommodation make the “SalmonFarms” business diversified. The local market showed a demand for sustainable products for the fisher industry. Own need and increased demand for the local provider for feeding fish in the cages lead the company to a new business that became a main investment at the moment. Catch herring and sprat by own fleet with subsequent production fishmeal and fish oil lead company for a new market, making it a leader and supporting sustainability. Catching and using local fish as feed for the salmon in the cages SalmonFarm reduces foreign nutrients and circulates the sea's nutrients. The fish caught in the Baltic Sea, processed into feed, and fed in local cages, is involved in phosphorus and nitrogen processing.
Finally, activities of the local company support sustainability, provide recreation services and improve food security in the region. All benefits were shared with the local community and people all over Finland, who decided to spend a vacation in that region. At the moment, the company are profitable and brings income for the owners. So, the conclusion that could be done that sustainable business brings benefits for all.
Photo Credits Karlis Dzjamko: Pexels
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A comparison between aquaculture facility on land and out to sea (on-land/offshore)
Producing over 50 percent of consumed seafood worldwide, aquaculture has become the world's fastest-growing food-producing industry, according to the United Nations Food and Agriculture Organization.
The risk of disease contamination is reduced by growing fish in land-based aquaculture systems, in closed and controlled environments. Fish production is completely natural and healthier as no antibiotics or disease treatments are involved in a normal production process. Carrying costs can be reduced as RAS technology is not entirely dependent on a specific water source and these land-based aquaculture systems can be built close to the market, resulting in a shorter time for transportation. Water pollution from the feed, feces, and chemical waste is being signified ally reduced by advanced filtering capabilities, making it a much more sustainable alternative.RAS allows continuous harvest round the year and compared to other methods fish grow to commercial size faster, In terms of efficiency and productivity. In RAS water temperature, oxygen, and carbon dioxide is controlled to their optimum level, which results in better conversion of feed to fish mass, lower contribution on the entire production chain, and lower production costs. On the other hand, it is comparatively risky and expensive setting up an offshore aquaculture farm, though there are a lot of offshore aquaculture farms existing which are paid off. A lot of uncertainty in the open ocean space is there. People aren't familiar with a lot of novel production technology. For example, a lot of new species in the open ocean are there.People are commonly concerned with traditional aquaculture species for example salmon, shrimp, and tilapia - as they know both production cost and profitable revenue. Also, the regulatory environment is completely different for different areas where people are thinking about doing open ocean aquaculture. Permitting the producers to operate in tropical waters can also have a positive impact on the production of the fish.
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Is Fish Farming a Fishy Business?
Do you care where the fish you buy comes from? If you are like me, a person concerned with the environment, then you should care. Fish farming was created to raise fish in a more sustainable way than wild caught fish. At least, that was the idea behind it. How can we trust the business? The main reason fish farms were created, was to keep up with the growing demand for seafood around the globe. But, with the rapid increase in demand, and consequently an increase in fish production, how can we be certain fish farming is keeping its words when comes to sustainabil
When fish are being overbreed, can they still be classified as sustainable? Some fish farms also fed with feed pellets containing GMO soybeans, in addition to antibiotics and hormones, which consequently, end up in our stomachs.
Check for labels! Just like other sustainable products, sustainable farm raised fish comes with labels on them. The more consumers demand for sustainability, the more they will be available. When we buy fish from fish farms, we are helping wild fish species, by protecting them from overfishing. Real sustainable fish farming do not use additives, chemicals, antibiotics, or hormones. Additionally, their fish is fed with vegetables. Sustainability comes with responsibilities. To be classified as sustainable, goes beyond just how you raise the fish, but also how you maintain an overall sustainable business operation. It involves monitoring, to make sure no wastes are produced, and to keep the water quality. They can also maintain their sustainability by using wind energy, producing drinking water from seawater, cleaning their own waste water, and making sure every part of the fish is used for a purpose. The goal is to not produce any waste.
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Raw Material and Waste Management
The current demand for salmon fish is skyrocketing. And to meet this demand, hundreds of fish farms have turned their attention to salmon fish production. However, in most cases, these fish farms are not economically and environmentally sustainable. Most fish farms are in a very bad position in waste management. So, at the same time, there is a need to meet the demand for salmon fish for all these people and focus on waste management for a sustainable environment.
Nowadays with the advancement of technology, the matter of waste management has become much easier than before. Most fish farms now use waste material as raw material for other purposes. If we think from that point of view, we can see that basically there is nothing as waste material, everything is being used as raw material. As interesting as the idea may sound, it is not. Many fish farms are coming up with a statement that they are not producing any waste, as all their waste is being used as raw material. But the matter is not one hundred percent true. Because these waste treatments are so expensive, fish farms often do not comply with them properly, because they have to keep the economy in mind.
Some salmon fish farms claim that they re-make fish meal with the waste material that the original product contains after marketing. This food is not given to all fish from which these waste materials come but is used as food for other species of fish. The next step is to make biodiesel from fish fat or use it to produce power. And all these products are used for fish farm maintenance. Which plays a very important role in the sustainable development of the fish farm.
Pharmaceuticals in Aquaculture
Aquaculture is one of the fastest growing industries in Europe. Growing demand for fish and shellfish gives business opportunities to farmers who are ready to take up the challenge to fulfil those needs. European aquaculture sector is very diverse but only half of seafood is farmed leaving the other half imported. Intensification of the industry is naturally needed to meet the public demand but at what cost...?
Salmon, shrimp, mackerel, tuna, rainbow trout or other seafood farming is much more prone to diseases than wild caught product. Of course, if it is done under strictly monitored and controlled conditions, it is possible to reach the highest quality standards from the beginning to the end. Unfortunately, along with intensity, there go problems. Lower immunity, health or reproductive problems are some of the many issues intensive seafood farming is facing. It is much easier for infectious diseases to spread in the water than it is on the land.
National, and international regulations approved a variety of pharmaceutical medicines that do not compromise a food safety for human consumption. Those include antibiotics, vaccines, or preventive medicines. One of the tactics preventing from human ingestion of any medicinal residue in the fish is the 'withdrawal period' that gives enough time between the end of the treatment and harvest of the animal. In comparison with 1990 when the use of antibiotics was at its peak, the overall use of those drugs has significantly decreased. For example, the use of antibiotics in seafood farming in Norway has lowered because of development of a batter vaccine. In 2004, Norway produced 23 times more salmon and trout than in 1985; in the same period, the use of antibiotics dropped by a factor of 25. (CONSENSUS). Unfortunately, not everyone tries to play fair and implement the healthiest solutions. China is the largest producer and exporter of aquatic products. However, the information about usage of antibiotics is very limited to public. Many seafood medications are not registered or are rejected due to high health risks, therefore their potential illegal usage can cause much more implications in human's health, for example causing cancer.
Bacteria, parasites, and fungal diseases also threaten aquaculture. European Animal Health & Welfare Research has published that limited availability of treatments and prevention tools is a serious constraint on the health management in fish farming. 304 different veterinary medicinal products are authorised for fish, against 10.000 for dogs and 8.000 for cattle. Half of them are vaccines, followed by antibiotics, representing the 29% of the treatments. Half of veterinary medicinal products are aimed to Atlantic salmon and trout (respectively 31% and 20%), while the 16% of them are directed towards a general category of fish. (FishMedPlus Coalition).
With the implementation of stricter rules and restrictions, pharmaceutical companies have more troubles registering medications and treatments for aquacultural use and their limited availability can lead to a massive product wastage that will not pass the health examinations for human consumption. Therefore, there is much more research to be done to find solutions for improvement for the seafood's and human's sake.
Personally, I first stopped eating fish for the ethical reasons, having in mind overfishing and bycatch. I could not determine whether the seafood I consume comes from a sustainable source or has it made its way to my plate by some other way. I want to be a responsible consumer and that requires me to be informed, seek scientifically backed up facts and not be ignorant, especially when it comes to my own health. I do not eat seafood and it is my own choice, what are you going to do about it?
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Feed to Food - Aquaculture
The world’s population is increasing exponentially and with it its demand for food.
This increased demand for food is causing problems regarding food security.
The production of animal protein requires feed, the rate at which an animal converts food into tissue is called the food conversion rate. The lower the food conversion rate is, the more efficient the animal is at converting feed into protein. In this blog, I’m going to be comparing the food conversion rates of farm-raised fish, poultry, and cattle. Hopefully, this comparison will help you make better choices in the foods you consume.
The most environmentally friendly option is to cut animal protein out of your diet entirely, however, this isn’t an option for a large part of the population.
As seen in the image below, farm-raised fish have the lowest feed conversion rate, followed by poultry, hogs, and lastly cattle. As you can see, farm-raised fish is roughly 6x more efficient in converting feed into animal protein than cattle. Next to this farmed salmon production emits fewer greenhouse gasses than cattle production. Making fish the most environmentally friendly animal protein available.
So if you haven’t yet decided what to make for dinner tonight and you aren’t vegan, maybe try some salmon instead of a steak. This way you help the environment and not only your belly will be satiated but also your conscience.
Global Aquaculture Alliance. (2021). https://www.aquaculturealliance.org/what-we-do/why-it-matters/. Retrieved from https://www.aquaculturealliance.org/what-we-do/why-it-matters/
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