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With regard to the number of animal and plant species, the Sea of Japan
is Russia’s richest sea, Peter the Great Bay showing best the wealth of
its flora and fauna. The cold Primorye Current descending from the
north meets a branch of the southern Tsushima current in Japan Sea, The
coast of southern Primorye is unevenly cut by numerous capes, inlets and
straits. Small rivers flow into bays. Animals inhabit some of the islands.
In hot months of the year, open sea waters warm up to 23oC, and in half-closed inlets up to 28oC. Only to the north of Nakhodka the water temperature is slightly lower than in the southwestern part of the sea. In winter, the water sharply cools. Given the water salinity (34), the temperature of littoral waters may be as low as minus 1.8oC. Due to the wide temperature range, the conditions in the sea are suitable for survival of subtropical fauna, and in winter for temperate and even arctic animals. Some animals have adapted to such conditions and some migrate to these areas temporarily. Thickets of sea grasses occupy vast littoral floor areas. Multicellular algae alone in Peter the Great Bay number 225 species. Laminaria are particularly abundant. This algae is called sea cabbage. Apart from collecting it from natural sites, laminaria is cultivated in large amounts on plantations, its harvests in Primorye being one of the highest in the world. Sea cabbage is used in both raw and preserved form for normal and remedial food. In recent years, people started to manufacture many beneficial substances from it, primarily sodium alginate. This substance is widely used in the food, chemical and textile industries. Other mass alga species are also economically significant. Agar-agar, so essential for confectioners and druggists, is obtained from gracillaria and ahnfeltia. Phyllospadia, from which expensive paper brands were formerly manufactured, grows on rocky soil under water. Its dried leaves were also used for manufacturing furniture. Fields of Zostera are commonly occur on slimy-sandy pebbly floor, and the young of many commercial animal species that subsequently settle over vast shallows spend their first days in those grasses. Phyllospadix and Zostera are higher plants. They cannot be considered algae. They flower and pollinate under water, but their flowers are unfortunately small and very inconspicuous. Since the sea is not decorated with flowers, generous nature has provided animals with the form and color of flowers. This primarily relates to Actinia—primitive animals, the closest relatives of algae. Incidentally, good divers can feast their eyes on large and beautiful Actinia in the Sea of Japan. The underwater landscape of bays is also decorated by Ascidia of up to 25 cm tall. They are reminiscent of a two-neck dark red carafe. |
Among algae and sea grasses, you can come
across numerous various little crayfish and shrimps at any time of the
year. The most well-known one is the herbacious species. The largest specimens
are up to 18 cm long. Yong individuals are of emerald color. Interestingly
enough, in its first year of life this crustacean develops into a male,
and then into a female. In winter, shrimps migrate deep into the sea.
Primorye is famous for its trepang
reserves. Indigenous inhabitants originally called Zolotoi Rog Inlet in
Vladivostok the inlet of trepangs. This animal is very popular in the countries
of the Far East and Southeastern Asia, and is sometimes called marine ginseng;
it is also expensive delicatessen food. Normally, the trepang lives
on rocky detritus, near boulders and Zostera thickets. Moving slowly over
silted sand, it captures soil particles with its feelers together with
microscopic organisms to digest them. It has been revealed that the biologically
active substances extracted from the trepang possess a wide pharmacological
and antifungal action. The Japanese Cucumaria that lives at great depths
and is widespread in all Far Eastern seas, resembles the trepang, and is
nutritious and beneficial in many respects.
Starfish and sea urchins are taxonomically
closely related to the trepang. Again, flat urchins live on sandy floor
sites, often having dug into the soil. Their shell is covered with dark
violet felt, as it were. Round urchins, mass representatives of Primorye’s
littoral fauna, are very prickly. Scientific studies of these animals have
led to numerous discoveries, particularly in embryology. Sea urchin
roe is very popular in Asia. In fact, commercial fishery enterprises in
Primorye presently land significant numbers of sea urchin for subsequent
export to Japan.
Starfish are mass inhabitants in highly
diverse underwater communities. Their skeletal plates consist of calcium
carbonate to impart them their unusual appearance. These amazing animals
delighted antique painters, and four thousand years ago images of starfish
used to decorate Cretan frescoes in Greece. In
Japan Sea, there are many starfish species. The ray span of the Amur starfish
is up to 32 cm. In quest of food, it crawls at 10 cm a second. This predator
feeds on the still slower, and sometimes even completely attached mollusks.
Patiria, another no less widespread starfish, is omnivorous. It occurs
in large numbers along the coast after storms.
Of animals, whose adult life passes
in attached state, the most well known species are oysters and mussels.
Pacific mussels frequently occur at small depths. They settle on banks,
which often encircle coastal rocks and cliffs in black belts. Neither wave
impacts, nor wind gusts in low tide frighten them. Special threads securely
retain them on the rock Thin valves that are bluish inside are constantly
ejected by waves onto beach pebbles and sand. One can convincingly say
that only their immense fertility saves them from complete destruction
by predator mollusks, starfish and fish. Significantly, mussels scale vessels
and hydraulic structures. On the other hand, being biological percolators,
they contribute greatly to purification of coastal waters.
In still deeper areas, you can come
across the world’s largest mussels, which are up to 20 cm long. The age
of such specimens may reach 100 years. Mussel flesh is tasty and beneficial,
but in some places and at a given time these mollusks may accumulate harmful
substances and microorganisms in doses dangerous to humans. Mussels are
nonetheless successfully cultivated in various countries. According to
world statistics, the annual mussel harvest is 40,000 tons.
The most promising object of commercial
fishing and cultivation in Japan Sea is the Primorye pecten. It moves by
ejecting water at abrupt clamping of its valves. The large lock-muscle,
situated in the middle of the shell, is a valuable food product with high
nutritional qualities.
The most well known and popular of
edible mollusks are naturally oysters. The giant or Pacific oyster lives
in the Russian Far East, Korea, China and Japan. It prefers to settle in
slightly freshened waters of bays at depths of up to 7 m. The mollusk can
both winter under ice and withstand the heat of sunrays in low tide. Its
shell size may be as much as 70 cm. In Peter the Great Bay, from late June
through August, you can watch oysters ejecting little turbid clouds. These
are roes. A large female would spawn them to as many as 100 million! When
fertilized, they develop to turn into larvae visible well only under a
microscope. The larvae would swim in the thick of water to be carried by
current over great distances. In one month, they would descend to the sea
floor to crawl in search of a suitable settling site and, having found
it, would attach themselves very firmly to underwater objects.
This oyster species was imported for
cultivation to successfully adapt on both seaboards of North America, around
Australia, Britain, France and many other countries. The world consumption
of oysters is about 770 thousand tons.
Primorye’s principal wealth is naturally
fish. Apart from valuable salmon species—the gorbusha, keta and brook masu
salmon, which live in the sea, but spawn in fresh water, current catches
mainly consist of mintai (Theragra chalcogramma). Several years ago, the
iwashi herring was also landed galore.
Mintai is the most numerous cod species
in the Pacific. In Peter the Great
Bay, it arrives only in winter and early spring to spawn
and fatten. The world catch of mintai amounts to 4 million tons, and half
of this goes to Russia’s credit. Although its rapid growth and maturation
maintain mintai reserves at a high level, its commercial fishery is regimented.
Today, a know-how has been devised to obtain tasty products from mintai,
e.g. salted roe and liver in oil, when only recently Russian fishermen
in the Far East regarded mintai as rubbish.
Only recently, iwashi, the Far Eastern
sardine, placed second in the catches of Russia’s fishery fleet. Six hundred
thousand tons were landed annually. Due to the high fluctuation in its
population, whose causes are not always clear to specialists, the commercial
catches are not constant. It was landed in large quantities until the nineteen
forties, when it stopped approaching Primorye shores to feed up. In the
nineties, Iwashi had returned in great numbers to previous fattening sites
to presently only leave again.
Herring is a very valuable commercial
species and highly popular among Russians. It is a typically gregarious
open sea species. The Pacific herring intensely fattens at the coasts,
feeding on small plankton organisms. Its fatness may be as much as 18-25%.
The herring population strongly fluctuates, too. Herring spawns its roe
on rocks, grasses and algae.
To enhance herring survival, biologists
have developed methods for creating artificial spawning grounds. Many amateur
fishermen in Primorye very much like to catch herring in late fall, when
it can grab empty hooks. At that time, people buy fishing licenses.
Among Japan Sea inhabitants, there are numerous
unusual and yet commercial animal species. These include the octopus and
squid. The giant octopus is one of the largest in the world. Its body alone
is 60 cm long, but together with the feelers its overall length sometimes
exceeds 3 m. Large specimens weighing about 50 kg live in underwater grottoes,
among heaps of stones, and under cliffs. Frogmen come across this interesting
animal quite often. Octopuses prey on various crabs, mollusks and fish.
By means of its suckers, the octopus can attach itself to the skin and
especially to the frogman/s suit; yet, there are no reliable cases of divers
being lengthily held, or moreover of their death. Small octopuses sometimes
occur in empty valves of large mussels. Placed in an aquarium, they would
eject an ink liquid to mask themselves and rapidly change their color.
A very well known species is the Kamchatka
crab. Its leg span may attain 150 cm. It is widespread from Korea to Bering
Strait and along the American coast at depths of up to 270 m. In early
April, it approaches the coast to reproduce.
The females are smaller than the males.
Commercial crab fishing is off limits. When mating, the male would hold
the female firmly with his claws. Even when surfaced, the male would for
a long time keep his mating partner in his claws. Crabs eat small mollusks,
crustaceans, worms and other sea floor inhabitants. Crab is obtained commercially
chiefly off the shores of Western Kamchatka, where in some years almost
eight million specimens were landed. Many years of crab fishery in different
places had reached its maximum. Recently the ban on crab fishing in the
northwest of Japan Sea was lifted, and Primorye fishermen began to land
about 1.8 thousand tons of crab annually. Significantly, the weight of
a giant crab equals 7 kg. The leg contents only is consumed as food. In
recent years, the valuable chitosan was obtained from the crab’s chitin
shell. The residue water remaining after preparing canned crab may be used
to prepare various aromatic additives.
As for aggressive and poisonous animals,
there are not too many of them in Primorye. Dangerous shark species occur
quite rarely in the coastal zone, and we do not know of cases when sharks
attacked humans.
The jellyfish may present the only
serious danger for swimmers at Primorye coasts. This medusa is small, not
more than 4 cm in diameter. Through its transparent dome, you distinctly
see a cross formed by its internal organs. The jellyfish lives at small
depths in quiet inlets. Most of the day, it hangs by securing itself to
underwater vegetation leaves to look out for small crayfish. The medusa
strikes its victim with special stinging cells on contacting it. The jellyfish
presents danger to humans because when its feeler contacts the skin it
poisons the body. The burn is accompanied by pain, and occasionally by
serious suffocation. Few serious cases were reported. In 1987, 239
ambulance calls were registered in Vladivostok to treat people stung
by medusas. In 1988, there were 214 calls, and in 1989, when the number
of medusas was larger, only 163 calls. In serious cases, the victim is
sent to the local toxicological center. As a rule, hospital treatment is
over after 3-4 days. People who like to frequent wild, remote beaches and
frogmen should avoid places overgrown with sea grass. The chance to meet
the jellyfish on an well-organized beach is very small.
Yu. YAKOVLEV, Cand. Sci. (Biology), Institute
of Marine Biology, Far East Branch, Russian Academy of Sciences.
