INTERNATIONAL WORKSHOP ON BLACK SEA BENTHOS 19-23 April 2004 ĠSTANBUL -TURKEY EDITORS Bayram ÖZTÜRK Vadim O. MOKIEVSKY Bülent TOPALOĞLU TÜDAV Publication No: 20 INTERNATIONAL WORKSHOP ON BLACK SEA BENTHOS All rights are reserved. No part of this publication may be reproduced, stored in a retrival system, or trasmitted in any from or by any means without the prior permission from the Turkish Marine Research Foundations (TÜDAV) Copyright: Türk Deniz AraĢtırmaları Vakfı (Turkish Marine Research Foundations) ISBN: 975-8825-04-6 This publication should be cited as follows: Öztürk, B., Mokievsky, V.O. and Topaloğlu, B. (Eds) International Workshop on Black Sea Benthos. Published by Turkish Marine Research Foundation Turkey 2004 245 pp. Türk Deniz AraĢtırmaları Vakfı (TÜDAV) P.K 10 Beykoz-Ġstanbul-TURKEY Phone: +90 216 424 07 72 Fax: +90 216 424 07 71 e-mail: [email protected] http://www.tudav.org Printed by Ofis Grafik Matbaa A.ġ. /Ġstanbul INTERNATIONAL WORKSHOP ON BLACK SEA BENTHOS 19-23 April 2004 ĠSTANBUL -TURKEY EDITORS: Bayram ÖZTÜRK Vadim O. MOKIEVSKY Bülent TOPALOĞLU CONTENTS Page PREFACE 1 THE BENTHOS OF THE OXIC/ANOXIC INTERFACE IN THE WESTERN 2 BLACK SEA: COMPARATIVE MACRO- AND MEIOFAUNA INVESTIGATIONS ON TRANSECTS FROM THE UKRAINIAN, ROMANIAN AND TURKISH SHELF Ulf LUTH A NEW TYPE OF MACROZOOBENTHIC COMMUNITY FROM THE ROCKY 70 BOTTOMS OF THE BLACK SEA Dragoş MICU, Sanziana MICU ANNOTATED CHECKLIST OF THE MARINE MOLLUSCA FROM THE 84 ROMANIAN BLACK SEA Dragoş MICU PRESENT STATE OF BENTHIC MACROPHYTE COMMUNITIES OF NORTH 150 CAUCASUS COAST OF THE BLACK SEA Dimitriy F., AFANAS’EV CONTEMPORARY DYNAMICS OF COASTAL BENTHIC COMMUNITIES OF 155 THE NORTH CAUCASIAN COAST OF THE BLACK SEA Margarita V. CHIKINA., Nikita V. KUCHERUK QUALITATIVE AND QUANTITATIVE INVESTIGATIONS ON ULVA RIGIDA 161 FACIES FROM THE UPPER INFRALITTORAL ZONE ALONG SINOP COAST, MIDDLE BLACK SEA Gamze GÖNLÜGÜR- DEMİRCİ and Tuncer KATAĞAN CONTRIBUTIONS TO THE KNOWLEDGE ON BENTHIC CRUSTACEANS 171 FROM TURKISH BLACK SEA COAST Gamze GÖNLÜGÜR, Tuncer KATAĞAN, Murat SEZGİN, Fevzi KIRKIM SPECIES DIVERSITY AND TYPE OF HARPACTICOID COPEPOD 177 DISTRIBUTION IN WATER AREAS WITH HIGH ANTHROPOGENIC INFLUENCE Lesya GARLITSKA CURRENT STATE OF THE ZOOBENTHOS AT THE CRIMEAN SHORES OF 185 THE BLACK SEA Nikolay K. REVKOV, N.G. SERGEEVA STRUCTURE OF BENTHIC DIATOMS TAXOCENES IN 215 MODERNCONDITIONS (Crimea, The Black Sea) Elena L. NEVROVA, Nikolay K. REVKOV, Alexei N. PETROV ECOLOGICAL ROLE OF BENTHIC AND PELAGIC INVADERS IN BENTHIC 237 ECOSYSTEM, THEIR BIOLOGY AND HISTORY OF INVASION M.Varshanidze.,A.Guchmanidze. PREFACE International Workshop On Black Sea Benthos, 18–23 April 2004, Istanbul-Turkey THE BENTHOS OF THE OXIC/ANOXIC INTERFACE IN THE WESTERN BLACK SEA: COMPARATIVE MACRO- AND MEIOFAUNA INVESTIGATIONS ON TRANSECTS FROM THE UKRAINIAN, ROMANIAN AND TURKISH SHELF Ulf LUTH Institut für Hydrobiologie und Fischereiwissenschaft, Universität Hamburg Keywords: Black Sea, Macrofauna, Meiofauna, Oxic/Anoxic Interface, Cluster Analysis ABSTRACT Results of benthic investigations including size classes from meiofauna to larger macrofauna from six transects in the western Black Sea are presented. Transects covered the depth interval from 50m to 250m depth including benthic environments from the shelf, the shelf edge and the upper slope. Special interest was set on taxonomic composition and distribution patterns of benthic communities inhabiting the depth zone where the oxic/anoxic interface meets the sea floor. The existence of a highly dynamic O2/H2S-transition zone on the sea floor is postulated being characterized by varying oxygen and/or hydrogen sulphide contents in the near bottom water. Besides variations in water conditions benthic communities from the shelf edge or upper slope also have to cope with instability of sediments induced by resuspension of sediments, turbidity currents or methane seeps. Shelf environments on the north-western shelf showed signs of strong eutrophication but also some indications for a restoration of benthic communities in recent years. Below a depth of 130m hardly any larger macrofauna was present similar to other investigations from the 1980’s. However, on most transects around 150m depth a densely populated benthic community of smaller size classes dominated by nematodes and oligochaetes, sometimes also with polychaetes and harpacticoids present, was found. From the upper anoxic zone around 190m mostly only few nematodes were obtained. INTRODUCTION The depth of the oxic/anoxic interface throughout the basin is largely determined by the meandering cyclonic rim current, which is, besides the meromictic water stratification itself, the dominating hydrographic feature of the almost totally enclosed Black Sea (SKOPINTSEV 1975; for detailed descriptions of the north-western Black Sea hydrography see TOLMAZIN 1985, and AUBREY et 2 al. 1996). The highly dynamic interface zone meets the seafloor at depths between 130m and 180m exerting major influences on the hydrochemical and biogeochemical conditions as well as the distribution of the benthic fauna of lower shelf and upper slope environments (LUTH & LUTH 1997). Interface dynamics have been the focus of a manifold of investigations (BLATOV et al. 1984, FASHCHUK & AYZATULIN 1986, BEZBORODOV et al. 1988, HONJO & HAY 1988, MURRAY et al. 1989, FASHCHUK et al. 1990, KEMPE et al. 1990, review by VINOGRADOV 1991, BEZBORODOV 1990, SAYDAM et al. 1993, BUESSELER et al. 1994, JONES & GAGNON 1994) but were restricted mainly to open water conditions far away from the shelf. Today the oxic/anoxic interface of the Black Sea is amongst the best known boundaries in marine science when the fields of hydrophysics, hydro-chemistry, marine microbiology and plankton research are concerned. Remarkably, the lower shelf and upper slope regions where the interface meets the seafloor received little to no attention. Especially, the dynamics of near bottom water conditions and benthic response remained beyond the focus of marine science. Traditionally benthic biology focussed on the vertical zonation of biocoenoses and the comparative investigation of the lower limits of benthic life in different regions and over time (CASPERS 1957, ZENKEVICH 1963, BACESCU et al 1971, KISELEVA 1981, ZAIKA et al. 1992) but mainly lacked detailed documentation of habitats and living conditions. Furthermore, most recent investigations on Black Sea benthos were either predominantly restricted to near shore areas (e.g. compiled in ZENETOS et al. 2000 for Ukrainian, Bulgarian, and Russian coast, STOYKOV & UZUNOVA 2001, Bulgarian coast and shelf) and/or larger size classes i.e. the macrobenthos (GOMOIU 1985, Romanian shelf) or single macrobenthic groups (e.g. MUTLU et al. 1992, MUTLU 1994, Turkish shelf, TERESHCHENKO et al. 1993, Ukrainian and Bulgarian shelf). The history of meiofauna investigation in the Black Sea (reviewed by SERGEEVA & KOLESNIKOVA 1996) demonstrates that numerous investigations on meiofauna of shallow waters have been conducted and many species, new to the Black Sea, have been described. Additionally, for example even for deeper benthic coenoses like the Modiolus phaseolinus coenosis certain assemblages of meiobenthic nematodes have been recognized (SERGEEVA, 1976). However, ZAIKA (1998) stressed the fact that former benthic investigations in deeper waters were generally conducted with bottom grabs which do not allow quantitative investigations of the smaller size classes like the temporary or larger meiofauna and ordinary meiofauna. Therefore, the knowledge on distribution patterns of these size classes across the oxic/anoxic interface zone throughout the Black Sea is still poor. 3 Linking Black Sea hydrography and benthos-The oxic/anoxic interface meets the sea floor: This work presents in part the results of a new approach trying to combine recent knowledge in Black Sea oceanography with benthic biology. The focus of this paper is set on the comparison of faunal distribution across the oxic/anoxic interface in three regions of the western Black Sea (Figure 1). The description of habitats and living conditions including short-term dynamics of the oxic/anoxic interface zone in the different regions will be addressed in detail elsewhere. However, for a better understanding of the interface dynamics in lower shelf and upper slope environments and their consequences for the benthic communities a short introduction to the matter is given. The numerous reports of depth variations of the oxic/anoxic boundary in central regions of the Black Sea (see above) together with few similar observations of this phenomenon in near shelf areas (KEMPE et al. 1991, LUTH & LUTH 1997, LUTH et al. 1998) allow the conclusion that the oxic/anoxic boundary also moves up and down near, or back and forth onto the shelf. However, there is no information so far, about amplitude and frequency as well as possible rhythms of these depth variations. Figure 1: Working areas in the western Black Sea: IN = Inebolu transect, SG = St. Gheorghe transect, S I and S II = Sevastopol transects I and II, CO = Constanza transect, PZ = Portiza transect. 4 Accepting depth variations of the oxic/anoxic interface on the sea floor as a given natural phenomenon for the Black Sea then each region should be characterized by an individual, average interface depth. From this depth in direction to shallower depths, the probability of an oxic regime increases whereas below this depth anoxic, sulfidic conditions become more and more likely. The limits of such a postulated O2/H2S-transition