The blue fields are blooming
It is summer again, the snow has melted, the days are getting longer and the first signs of new life have peppered the landscape with colour. Along the coast the blue fields are also blooming. The early bloom is over, but the results are evident.
The changes in the sea that take place every spring can best be described as a cascade of events triggered by the increase in sunlight.
Plants and algea come alive!
The sunlight awakens myriads of microscopic plants, microalgae, which start to grow and multiply at high speed. But as is the case for sun-hungry Scots in Spain, the sun alone is not enough. Nutrition is needed in order to grow. Winter storms and waves have broken down the layers in the coastal waters, layers that formed during the summer months. The warm layer at the top loses nutrients quickly, and dead and dying algae sink down to the bottom and rot. This layer is broken up during the winter and the nutrient-rich water from the bottom moves up to the surface again. Run-off from the land, especially during the spring thaw, also adds nutrients that are easily accessible to algae as soon as there is sufficient sunlight. The clear blue coastal water first becomes murky and then gradually adopts a greenish colour. The characteristic green colour comes from microalgae with catchy names such as coccolithophore, diatoma and dinoflagellates, and it dominates during the blooming period. There are different algae in different locations, but the common denominator is that the sea becomes green/brown in colour.
Without the spring bloom – no life in the sea!
The spring algal bloom is at the core of existence for all sea species. Some species, such as fish fry, are an invaluable resource for the coast, while other species can cause problems for ships and aquaculture.
The more problematic species include mussels, bryozoans, hydroids and the invasive skeleton shrimps.
If we take mussels as an example, some of the factors that make them a good candidate for aquaculture are also what make them a nuisance for fish farms.
Mussels filter their food from the water around them. Under natural conditions, they will subsist on microalgae and other particles. In the vicinity of a fish farm, however, there will be large quantities of additional nutrients from feed and fish waste. This substantially increases the growth potential and survival rate of the mussels and other fouling species. Research shows that these species can grow much faster on and around a fish farm than would be usual under natural conditions in the same area. The larvae of fouling species are also more predominant around a fish farm.
Mussels grow quickly and can become a considerable problem for fish farmers within a short space of time. Given sufficient light and microalgae, they will attach themselves to the nets, and it is common to see large numbers of mussels (and observe the problems they cause) on moorings and fish farm facilities as early as the end of April / beginning of May.
A classic summer dish
The Irish sang about Mary Malone and her mussels, and it is a fact that mussels and other delicacies from the sea have always been part of the staple diet of the coastal population. We recommend the following recipe for those balmy summer evenings!
Freshly steamed mussels are a perfect summer dish, whether served on the terrace or the pier.
Serve with fresh bread.
For 4 people:
1 kg mussels
1 red chilli
1 dl fresh coriander
1 dl Thai basil
2 dl beer
2 spring onions
Wash the mussels.
Throw away mussels that do not close when you press them or ones that are damaged.
Chop the vegetables and herbs.
Quickly fry the vegetables in some oil and add the mussels and beer.
Cover with a lid and steam until the mussels open.
Chop the spring onions.
Sprinkle over more basil, coriander and finely chopped spring onion and stir gently.
The most common species. Click icons below
JJohn is Sales Manager at Steen-Hansen. He has worked with nets for an entire generation, among other things as general manager of a service station.
Discussions with John are not limited to the protection of nets and reduction of fouling. He also has a broad knowledge about nets, net materials and the construction of nets.
email@example.com / +47 94010670
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