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Temp: Bottom 13°C
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Dive type : Recreational
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Visibility: Average
Water: Salt
Recent Divers in Kirkkonummi
Dive Shop & Buddies
Dive buddies:
Tommi Muona
Dive Profile
- 1. Air
- 12L Steel
210 → 70 bar
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- Average depth: 11.3m
Data provided by EOL.org
Species Identified
Perca fluviatilis Linnaeus, 1758 (European perch)
Perch live in schools, often mixing with other species of fish, usually in the top 50 metres of water. Spawning takes place in April, the very sticky eggs being produced in bands. Females twine these bands around submerged...
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Perch live in schools, often mixing with other species of fish, usually in the top 50 metres of water. Spawning takes place in April, the very sticky eggs being produced in bands. Females twine these bands around submerged vegetation or among rocks while the males follow her and fertilise the eggs. The young fish hatch after about three weeks and remain amongst the egg bands until the yoke sac is exhausted. They then venture into more open water and feed on planktonic animals. As they grow they begin to shoal together close to the bank. Males mature when they reach the length of 7 – 8 cm, females when they are 10 cm.
Mytilus edulis Linnaeus, 1758 (edible blue mussel)
The mussel is a filter-feeder; it filters bacteria, plankton, and detritus from the water . When large beds of this gregarious species form, individuals are bonded together with threads of byssus. Predation is the greatest...
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The mussel is a filter-feeder; it filters bacteria, plankton, and detritus from the water . When large beds of this gregarious species form, individuals are bonded together with threads of byssus. Predation is the greatest cause of mortality; a range of predators take mussels, including dog-whelks (Nucella lapillus), crabs, sea urchins, star-fish, and birds such as the oystercatcher (Haematopus ostralegus) . Although mussels seem fairly defenceless, remarkably they are able to fend off marauding dog whelks and other predatory gastropods; a number of mussels work together to immobilise the predator with bysuss threads . Organisms that attach to mussels, such as seaweeds and barnacles, may increase the risk of the mussel becoming detached by wave action; however, mussels are able to sweep their foot over their shell, which may help to minimise the likelihood of such an organism becoming attached . The sexes are separate, fertilisation occurs externally and spawning peaks in spring and summer . The larval stage is free-swimming and planktonic for around 4 weeks , before settling first on filamentous organisms such as seaweeds . After growing for a while, they detach and drift in the water on a long byssal thread; a mode of dispersal likened to that of young spiders floating through the air on a silk thread . After four weeks or so, the young mussel will have settled again, this time on a mussel bed . Young mussels are thought to have evolved primary settlement on filamentous substrates in order to avoid having to compete with adult mussels . Mussels are host to the pea crab (Pinnotheres pisum), and a copepod (Mytilicola intestinalis), both of which are not parasites, as was once thought, but commensal organisms . Furthermore, mussel beds provide habitats for a variety of marine life, and support higher levels of biodiversity than surrounding mudflats . The biodiversity of the bed increases with its size and age .
Aurelia aurita (Linnaeus, 1758) (moon jelly)
The common jellyfish is carnivorous, and feeds mainly on a variety of planktonic species such as molluscs, crustaceans, young worms and copepods . The plankton is caught in a layer of mucus that covers the jellyfish. Tiny ...
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The common jellyfish is carnivorous, and feeds mainly on a variety of planktonic species such as molluscs, crustaceans, young worms and copepods . The plankton is caught in a layer of mucus that covers the jellyfish. Tiny hair-like structures called 'cilia' on the body of the jellyfish produce currents by beating. These currents transport the captured plankton towards the edge of the 'bell', where it is removed with the arms and passed to the mouth . The tentacles around the margins of the bell and the arms bear stinging cells, which are occasionally used to catch small fishes and other prey . The sexes are separate and fertilisation occurs internally; the sperm is taken into the female's body via the mouth . The fertilised eggs undergo development in pockets in the arms that surround the mouth. The free-swimming larvae (known as 'planulae' larvae) are released during autumn; after some time these larvae settle and develop into tiny sessile animals ('scyphistomae'), which reproduce asexually and release free-swimming tiny immature jellyfish (called 'ephyrae'), which feed on plankton and become mature after around 3 months .
Pungitius pungitius (Linnaeus, 1758) (Ninespine stickleback)
Found in shallow vegetated areas of lakes, ponds, and pools of sluggish streams; sometimes in open water over sand . Marine populations found near shore and move into fresh water to spawn . There appears to be seasonal m...
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Found in shallow vegetated areas of lakes, ponds, and pools of sluggish streams; sometimes in open water over sand . Marine populations found near shore and move into fresh water to spawn . There appears to be seasonal movements inshore to shallow water in the spring for spawning, and, in the fall, offshore to deep water, or even to the less saline parts of the sea, by the young and adults that survive spawning . Nerito-pelagic . Feeds on small invertebrates; also on aquatic insects and their eggs and larvae . Eggs are found in nests constructed from plant material . Females grow faster and live longer than do other males . Males seldom live beyond age three, due to heavy post-spawning mortality, but females may live to age five or more . When abundant, it is preyed upon by other fishes ; also preyed by birds . May be used as human or dog food or as a source of oil .
Gymnocephalus cernuus (Linnaeus, 1758) (blacktail)
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Petri Hirvonen
Finland
Date: 2008-09-24 - 18:35
Max Depth: 16.9m Duration: 35mins
Nice evening dive at Porkkala. More sea life than usual. Clear weather, very light winds. Air temp. 15°C. Water surface flat.
Photo from the buddy Tommi Muona's site: http://teamdiver.org/tommi/