Journal of Coastal Research 1119-1133 Royal Palm Beach, Florida Summer 199H The Arthropod Community, Especially Crustacea, as a Bioindicator in Algeciras Bay (Southern Spain) Based on a Spatial Distribution J.E. Sanchez-Moyano and J.C. Garcia-Gomez Laboratorio de Biologia Marina Dpto. Fisiologia y Biologia Animal Facultad de Biologia Universidad de Sevilla, Apdo. 1095 41080 Sevilla, Spain ABSTRACT . SANCHEZ-MOYANO, J.E. and GARCIA-G6MEZ, J.C., 1998. The arthropod community, especially crustacea, as a .tflllllll:. bioindicator in Algeciras Bay (southern Spain) based on spatial distribution. Journal ofCoastal Research, 14(3),1119­ ~ 1133. Royal Palm Beach (Florida), ISSN 0749-0208. Spatial variation of the arthropod communities of the alga Halopteris scoparia in relation to the influence of environ­ eusss------ ~ 7# --a... cz;-&is mental factors in the Algeciras Bay (Southern Spain) was investigated by means of multivariate analyses. We have been able to determine a clear separation in composition of communities between external and internal areas of the bay, with hydrodynamism and algal morphology being the most determinant factors. In the external zone a greater number of species appear, whose quantitative dominances are more even than among the species of the internal zone, where some clearly dominate over the others, e.g., the amphipods Corophium acutum and Jassa marmorata. Crus­ taceans show in a clear way the differences among the localities and are useful in characterization studies of envi­ ronmental quality of coastal waters because of the abundance, high species richness and the wide environmental spectrum in the epiphytic communities ADDITIONAL INDEX WORDS: Epifau.na. enoironmental factors, hydrodynamism, sedimentation. habitat complexity, canonical correspondence analysis, Halopteris scoparia, Southern Spain. INTRODUCTION the intraspecific variations provoked as well by the different environmental conditions will be less than among various The arthropods, and more specifically the crustaceans, substrata (SANCHEZ-MoYANO, 1996). According to HACKER have been often used in macrophytobenthic studies (BIBI­ and STENECK (1990), it is a branching alga within a small LONI, 1981; JIMENO, 1993; CASTELLO et al, 1987; GARCiA­ space. This means, on the one hand, that the abundance of RASa, 1988; COSTELLO and MYERS, 1987) to show various individuals will be high because of the great quantity of avail­ relationships of predation and competition (NELSON, 1979a able microhabitats, in addition to constituting a good sedi­ and b; COEN et al. 1981; GUNNILL, 1984; EDGAR, 1990a and ment and periphyton trap (especially diatoms which consti­ b; HOLMLUND et al, 1990; POORE, 1994) or to establish the tute the diet of most of the epifauna-Orth and Van Mont­ environmental patterns that control the communities (BEL­ frans, 1984), and additionally, it restricts the size of the or­ LAN-SANTINI, 1964, 1966; FENWICK, 1976; STONER, 1983; ganisms. It is one of the most abundant algal species and AOKI, 1988; PROCACCINI and SCIPIONE, 1992; Russo, 1989; most widely distributed in Algeciras Bay. This bay, located AOKI and KIKUCHI, 1990; ARRONTES and ANADON, 1990; in the most eastern zone of the Strait of Gibraltar, is com­ CONRADI, 1995; among other). In this sense, the crustacean posed of heterogeneous environments imposed by the natural communities have been considered as one of the most sensi­ configuration of the coast as well as by intense port and in­ tive to the changes produced by environmental variables dustrial activity. This makes diverse environmental condi­ (DOMMASNES, 1968, 1969; DESROSIERS et al, 1982, 1986 and tions in spite of its relatively small extent (approximately 30 1990; MOORE, 1986; GRAHAME and HANNA, 1989). km long with a width of 8 km at its extreme), something Our objective has been to analyze variation in the compo­ which must influence the composition of the associated ar­ sition of arthropod communities (mainly crustaceans) asso­ thropod communities. ciated with the alga Halopteris scoparui (L.) Sauvageau (Phaeophyta, Sphacelariales) in relationship to the various MATERIALS AND METHODS environmental conditions found in the Bay of Algeciras (Southern Spain). The selection of this algal species was to A total of 13 sampling stations were chosen and grouped eliminate the variations in structure of the community pro­ in five areas distributed along the coast of the Bay of Alge­ voked by configuration of the alga, assuming, of course, that ciras in order to encompass the broadest range of environ­ mental conditions (Figure 1). Island las Palomas (IP) is a pho­ 97091 received 11 June 1997; accepted in revision 5 October 1997. tofile rock zone and located in the extreme west of the bay. 1120 Sa nchez -Moya no an d Carciu-Gomcz F i~ lI l'e I. Location of the sampling stations in Algeciras Bay . Punta de San Ga rcia (SG), with simila r cha rac teristics, like a parab oloid, the theo re t ical volume was calcula ted from though a sciafile environme nt in more sha llow waters. In this . Deducting t he real volu me from th e th eoreti cal one we both a reas, the stations were es ta blis hed in a tra nsect 200 obtained the interstitial volume, whic h rep resen ts th e living met ers long and 5, 8 and 10 meters deep . Inl et of th e Cuca reo space. The rela tio ns hip betwee n th e th eoreti cal volume and (CU ), nearby area to th e Port of Algecir as, is located on a the real one gives an idea of the level of compactness of th e wide platform t hat va ries between 3 and 5 met ers deep . The alga (Index of Compac tness), in such a way th at how much stations were es tablished on a transect of 200 meters. All more is approximate d to one it will be more compact. Th is stat ions wer-e nu mbered beginning from th e most shallow. com pactness can measure th e habi tat complexi ty . Los Rocadillos (Guadarra nque l (GU ) is located in the internal In orde r to establish which paramet ers influen ce th e com­ zone of the bay, nea r th e mouth of th e Gua da rranque River positi on of the a rthropods communities some concrete mod­ on a natural rock band along the coast, between 3 an d 5 me­ ules were soun de d along th e arch of the Bay (Fig ure 2l. The ters deep . Unable to establis h transects in depth, th e two samplings were tak en monthly from November of 1992 un til stations were located according to th eir distance from th e out­ Nove mber of 1993. let : GU 1, th e fartherest; an d GU2 . In th e internal zone, Cri­ Th e va ria bles measured were: maximum and mini mal tem­ navis (CRI is a a rti ficial su bstra tum belonging to a shipyard peratu re, hydrodyn amism , sedime ntation rate, 'h orga nic in disuse. The stations were located along thi s breakwater, ma tter of th e sedimentation, solid a nd 'h of organic matter to a depth of [) meters. in suspension. Four repli cate samples were taken at eac h station during For hydrodyna mism (or wa ter movement ), th e meth od of five samplings th roughou t one yea r (Se ptember 92; Decem ber "plast er dissolution" described by Mu us (1968) a nd modified 92; March 9:~ ; .I une 9:1; and Se ptember 9:3). Eac h sa mple con­ by GAMB I ('I al (]989) was used, measured as "equivalent sists of a n alga specimen, pocket ed ill si tu and extracted from speed of th e water" (V) (BAILEy-BROCK, 1979l. t he bottom by SCUBA diving. The sedimentation rate was measured by t he placemen t of T IH' samples wer e put thro ugh a sieve of 0.5 rnm of light sediment trap s (six bottl es of a lit er capac ity in our case). mesh and we re th en separated, classified and qu an t ified into Part of th e sedime ntation is use d to ca lcu late the 'h of organic t ill' dint-rent species . Th e ab un da nce data were in te rms of matter thro ugh ca lcination at 500 0 C. Th e data are expressed number of indiv idua ls per 100 dry weight grams of alga . as gr/m"/mo nth. On ce t he fauna were sepa rated, a series of statist ics was Th e solids a nd organic matter in sus pension wer e mea­ ca lculuted fill' eac h alga: wet a nd dry weight, maximum sured acco rdin g to the method of STRI CKLA ND and PAIiSO" Iwight , d iam eter a nd volume. The volume was estimated by ( Hl6~») . wa ter displacement of the a lga in a manometer. Ass uming Th e poss ible spatia l variations of th ese variables were test­ t hat II. scopuriu adopts a geometric form in t he environment ed through one-way ANOVA, a fte r verifying normality (Kol- .Iournal Ill' Coasta l He" ""'"h , Vol. 14, No.:1. I!J9H Arthropod Community as a Bioindicator in Algeciras Bay 1121 ~M 10 4 r l 1·· I. BIL] 2t - 1 I oj L_--1- ~-----t- -~~t-~~~-'-~-·T ._.. ~~--~.+- .. ~ ......- .. -..~ .-- ..-..... -.- ... ~ G U 2 ~• GU1 ACX CR2' CR / Figure 2. Variation of the environmental parameters in the stations. The thick line corresponds to the median; the rectangles contain 50(1, of the valucs, between 1,;' and 3 r d quartile; the thin lines connect the extreme values, unless located at a distance superior to 3 times the height of the rectangle than they are indicated by an asterisk.