The morphology and sculpture of ossicles in the Cyclopteridae and Liparidae (Teleostei) of the Baltic Sea

Small to very small bones (ossicles) in one species each of the families Cyclopteridae and Liparidae (Cottiformes) of the Baltic Sea are described and for the first time illustrated with SEM images. These ossicles, mostly of dermal origin, include dermal platelets, scutes, tubercles, prickles and sensory line segments. This work was undertaken to reveal characteristics of the morphology, sculpture and ultrasculpture of these small ossicles that could be useful as additional features in taxonomy and systematics, in a manner similar to their use in fossil material. The scutes and tubercles of the cyclopterid Cyclopterus lumpus Linnaeus are built of small denticles, each having its own cavity viscerally. The thumbtack prickles of the liparid Liparis liparis (Linnaeus) have a tiny spinule on a porous basal plate; the small size of the prickles seems to be related to their occurrence in the exceptionally thin skin, to an adaptation for minimizing weight and/or metabolic cost and possibly to their evolution from isolated ctenii no longer attached to the scale plates of ctenoid scales. Nodular ultrasculpture was found on the tubercle denticles of C.lumpus, resembling some kinds of ultrasculpture seen in Palaeozoic vertebrates. Samples from the posterior part of the head of C. lumpus and the anterior part of the trunk of L. liparis each contained an ossified sensory line segment with distinct characteristics, as also reported in other cottoids

The morphology and sculpture of ossicles in the Cottidae (Teleostei) of the Baltic Sea

Small to very small ossified structures (ossicles) such as cephalic horns, dermal tubercles, fin-ray rods, lateral-line canal segments, branchial tooth plates and gill-raker tubercles of three species of the teleostean fish family Cottidae inhabiting the Baltic Sea are described and for the first time illustrated with SEM images, with emphasis on their microscopic external features. The morphology and sculpture of these small ossicles notably differ in the three genera, but differences can also occur between males and females, as documented here in Myoxocephalus scorpius (Linnaeus). The detailed features of such ossicles are potentially useful for taxonomic identification in sea-floor sediments or gut contents, in a manner similar to their use in many modern and fossil fishes, and may also prove useful as phylogenetically important characters at generic and familial levels

Collapse of Political and Economical System as a Cause for Instability in Fisheries Sector: An Estonian Case

The transition process from the Soviet economical system to the market economy in fisheries has received relatively little attention from fisheries researchers. This study analyze how overall changes in political and economical life of Estonia during the last decade have affected the complex system of the environmental, economic, social and legal issues connected to the coastal fishery of the Baltic Sea. At the beginning of the nineties the possibility to export fish to the European market appeared. Opening of this new and highly profitable market outlet resulted in rapidly increasing pressure to the fish resources, both in terms of the number of fishermen and in their effort. Some of the most important coastal fishery resources have been over-fished because of high export market demand coupled with insufficient resource management, and not effective enough control and enforcement capacity. The costs connected to fishery have grown much more than the first buyer prices. Additionally, dynamic development of the Estonian economy has yielded in substantial increase of wages in other sectors of economy and therefore the well-being of fishermen has steadily worsened. This has resulted in increasing social problems. The conclusion is that countries in transition may encounter serious difficulties in the fishery sector arising from privatization and rearrangement of financial system, which may affect the fishery even years after the establishment of new ruling principles

Kalakasvatusliku taastootmise programm : programm "Riiklikku kaitset vajavate ja ohustatud kalaliikide kaitse ja kalavarude taastootmine (2002-2010)"

TäistekstKäesolev programm on Eesti Vabariigi keskkonnaministri poolt käskkirjaga nr 352, 06.05.2002 kinnitatud juhend kalakasvatusliku taastootmise riikliku poliitika elluviimiseks Eestis, mis käsitleb kõigi praegu või eeldatavasti lähemas tulevikus Eesti veekogudesse asustatavate kalade taastootmise põhimõtteid ja näitab ära kaitset vajavate (ohustatud) kalade taastootmise riikliku finantseerimise prioriteedid ning kalapüügivõimaluste laiendamiseks vajalike kalade asustamiste toetamise prioriteedid. Programmis toodud asustusmahud ja kohad on soovituslikud ja lähtuvad 2001. aastal prognoositud reaalsetest võimalustest.Taustanalüüs. Kalavarud on tähtis taastuv loodusvara, mille kasutamine peab olema kooskõlas nii rahvusvaheliselt kui Eestis heaks kiidetud säästva arengu põhimõtetega. Eesti säästva arengu seadus sätestab, et loodusvarade säästva kasutamise eesmärgiks on tagada inimest rahuldav elukeskkond ja majanduse arenguks vajalikud ressursid elukeskkonda oluliselt kahjustamata ning looduslikku mitmekesisust säilitades. Kalade arvukuse säilitamise või suurendamise põhimõttelised võimalused on: 1) püügi reguleerimine kalapüügieeskirjas määratud piirangutega (keeluajad ja -piirkonnad, lubatud püünised ja alammõõt jne) ja püüniste arvu või kalakoguse limiteerimisega; 2) elukeskkonna (eeskätt sigimisvõimaluste) kaitse, parandamine või taastamine; 3) kalakasvatuslik taastootmine (kalakasvandustes üleskasvatatud noorkalade asustamine veekogudesse, edaspidi lühendatult taastootmine). Viimane on kulukas tegevus, mis eeldab pikaajalist planeerimist ja otstarbekuse analüüsi. Kalade kaitsemeetmed on sätestatud mitmetes õigusaktides ja dokumentides. Loodusliku mitmekesisuse kaitse huvides on Eestis vastu võetud mitmeid programme, mis puudutavad ka kalu. Igakülgsete kaitsemeetmete väljatöötamine jätkub seoses Eesti ja Euroopa Liidu keskkonnakaitse poliitika harmoniseerimisega. Tehistingimustes peetud loomade loodusesse laskmine (seega ka kalade asustamine kalakasvandustest) toimub loomastiku kaitse ja kasutamise seaduse § 19 järgi keskkonnaministri poolt kinnitatud programmi alusel. Käesolevas programmis on koondatud tähelepanu ohustatud ja majanduslikult kasutatavate kalaliikide arvukuse suurendamisele kalakasvatusliku taastootmise kaudu. Eesti 74 kalaliigist (Saat, 1992) on 8 inimtegevusest ohustatud (neist 4 on looduskaitse all), veel 4 liigi arvukus oleneb tugevasti inimtegevusest. Osa ohustatud liikidest on samal ajal kalanduslikult tähtsad ja neid püütakse pidevalt. Eestis on ka 7 liiki Euroopa Liidus (EL loodusdirektiivi alusel) ohustatuks loetud ja kaitstavaid kalu (sh kolm sõõrsuuliiki), mis on meil kas harva esinevad eksikülalised või pole siin otseselt ohustatud. Kalavarude suurendamiseks ja püügivõimaluste loomiseks taastoodetakse või on toodetud 5 mitteohustatud liiki. Majanduslikult kasutatavate veeorganismide hulka kuulub peale kalade ka inimtegevusest ohustatud jõevähk, mistõttu sellekohaseid probleeme käsitletakse käesolevas dokumendis koos kaladega. Sellise mitmekesisuse tõttu tuleb vaadelda Eestis riiklikku kaitset ja taastootmist vajavaid kalaliike rühmadena, mille suhtes rakendatavad meetmed ja riikliku toetamise vajadus on erinevad. Forelli ja siia liigisiseseid vorme käsitletakse nende ökoloogia erinevuste tõttu eraldi

The transition from the Soviet system to a market economy as a cause of instability in the Estonian coastal fisheries sector

This study analyzes how overall changes in political and economic life during the last decade have affected the Estonian coastal fishery of the Baltic Sea. At the beginning of the nineties, the opportunity to export fish to the European market emerged. Opening of this new market resulted in rapidly increasing pressure on fish stocks. Some of the most important coastal fishery resources were over-fished because of high export market demand coupled with insufficient resource management and ineffective control and enforcement mechanisms. The costs associated with fishery have grown much more than the first-buyer prices. Additionally, dynamic development of the Estonian economy has resulted in substantial increases in earnings in other economic sectors and therefore the relative wealth of fishermen has steadily declined. This has resulted in increasing social problems. In conclusion, countries in transition may encounter serious difficulties in the fisheries sector, arising from privatization and economic reforms, which may affect the fisheries even years after the establishment of new ruling principles.Estonia Coastal fisheries Fisheries development Trade liberalization Transition to market economy