Characteristics of the Introduced Fish Fauna of Israel
Total Page：16
File Type：pdf, Size：1020Kb
Biol Invasions (2007) 9:813–824 DOI 10.1007/s10530-006-9083-8 ORIGINAL PAPER Characteristics of the introduced fish fauna of Israel Uri Roll Æ Tamar Dayan Æ Daniel Simberloff Æ Menachem Goren Received: 7 November 2006 / Accepted: 5 December 2006 / Published online: 16 January 2007 Ó Springer Science+Business Media B.V. 2006 Abstract Fishes have been introduced world- Keywords Alien species Á Aquaculture Á wide with deleterious effects on various native Biogeographic origin Á Fish Á Impact Á Israel Á ecosystems. To gain insight into this phenomenon Restocking in Israel, we studied the introduced ichthyofauna. There are 27 species of introduced fishes in the freshwater habitats of Israel, a large number for a Introduction nation this size. Ten of these species reproduce in the wild. Most of these fishes were introduced for Fishes have been introduced unintentionally and aquaculture; some are constantly restocked. The intentionally for various reasons to many regions proportion of restocked versus established species (Welcomme 1988). The introduction the Nile in Israel is high compared to other regions. New perch (Lates niloticus) into Lake Victoria is often fish introductions continue in recent decades, cited as one of the most damaging introductions unlike the global trend. In Israel these species are to native ecosystems (Goldschmidt 1996), and found in the Jordan Basin, Lake Kinneret (Sea of there are many other records of deleterious Galilee), and the coastal plain rivers. A few effects of introduced fish on local biodiversity species are widespread, and most are found in (e.g., Vredenburg 2004; Goren and Galil 2005). Lake Kinneret. Harmful effects of introduced Introduced fishes can affect local ecosystems in fishes have been suspected and in several cases diverse ways (Simon and Townsend 2003). They demonstrated. We encourage further caution can prey upon, hybridize with, or outcompete when new introductions are contemplated; in native species (Arthington 1991; Crivelli 1995; some regions eradication should be attempted. Debrot 2003; Kats and Ferrer 2003; Mills et al. 2004), they can transfer pathogens and parasites (Josefsson and Andersson 2001), cause commu- nity level changes (Beisner et al. 2003; Irz et al. & U. Roll ( ) Á T. Dayan Á M. Goren 2004), and even facilitate the introduction of Department of Zoology, Tel Aviv University, Tel Aviv 69978, Israel other taxa (Adams et al. 2003). Several works e-mail: [email protected] characterize attributes of fishes introduced suc- cessfully (Rosecchi et al. 2001; Kolar and Lodge D. Simberloff 2002; Marchetti et al. 2004) and habitats that are Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996-1610, more susceptible to introduction (Moyle and USA Light 1996). 123 814 U. Roll et al. Israel is situated at edge of the Saharo-Arabian duced fishes in Israel focusing on various relevant desert belt, and it boasts both arid and temperate traits. We also address the general characteristics climates (Jaffe 1988). The northern half of the of the fish introduction phenomenon and its country receives the majority of annual rainfall, impacts in this region. which flows either westwards in many streams and rivers towards the Mediterranean Sea or east- wards into the Jordan River basin. Eleven of the Methods rivers flowing west and seven of the rivers flowing east carry water, at least along part of their We gathered data from personal observations, the length, throughout the year (Yom-Tov and Men- Natural History Collections of the Tel-Aviv delssohn 1988). The Jordan River and its tribu- University, and published works (Goren and taries flow in a general north to south pattern. Ortal 1999; Golani and Mires 2000). For general The Jordan River passes through Lake Kinneret species-specific data, we collected information (the Sea of Galilee), which is situated 209 m from Welcomme (1988) (now published and below sea level. This lake, with an area of revised online under the FAO’s website) and 166 km2 and maximum depth of about 43 m, is ‘‘FishBase’’ (Froese 2006). the main open source of fresh water for Israel. For each species we recorded systematic affin- Israel’s natural freshwater bodies have been ity, various life-history attributes, food habits, anthropogenically altered in the past century body mass, geographic range of native popula- (Yom-Tov and Mendelssohn 1988). Most of the tion, geographic range of source population for swamps (both along the Mediterranean coast and this introduction, new geographic range in this inland) have been drained. In 1957 the largest of region, history of spread in this region and in the these, the Hula swamp (and adjacent lake), which world, local dispersal methods, means of intro- was an unusual habitat, was drained (Yom-Tov duction to this region, ecosystems invaded, year and Mendelssohn 1988). Most of the water from of first discovery in this region, known economic the river systems is used by humans, and in most or environmental impact (in this region), known streams the remaining water is polluted. Only one records from elsewhere of this species as an of the rivers flowing west is slightly or not introduction, and status of the species in this polluted. In the rivers flowing east, there are region. extreme reductions in the amount of water, as We assigned the species to three freshwater they are used for irrigation. In addition to these systems according to Goren and Ortal (1999): changes, various species have been introduced Lake Kinneret, Jordan River system (local and into different freshwater habitats. widespread), and Coastal Plain rivers. In the upper reaches of the Jordan River the water quality is good. Lake Kinneret is more saline, however; some of the more saline springs Results that used to flow into this lake have been diverted, and it now contains around 240 ppm of Status of introduced fishes in Israel chloride ions (Fishelson 1983). Lake Kinneret’s outlet is dammed, and downstream from it, up to Currently 41 fish species are known to have been the Dead-Sea, the Jordan River is a shallow, introduced to freshwater habitats. We assigned polluted stream. The Dead-Sea itself is hyper- them to five status categories in accordance with saline (up 27% salts) and supports no fish. Welcomme (1988): Three recent studies have treated introduced fishes in the freshwater systems of Israel (Goren • Never became established—species that either and Ortal 1999; Golani and Mires 2000; Goren are not found in wild habitats, or were found and Galil 2005). These sources emphasize specific in wild habitats as few individuals and subse- species’ details and do not analyze them cumula- quently disappeared (12 species, one of which tively. Here we provide an overview of intro- is an introduced subspecies). 123 Characteristics of the introduced fish fauna of Israel 815 • Does not reproduce in the wild—species Fisher’s exact test); Israel has a higher proportion found in the wild that retain their populations than Europe of fish that must be restocked to through either continuous restocking or ongo- persist. ing escape from fish farms. However to our knowledge, these species do not reproduce in Characteristics of the introduced fishes of the wild (to date) (17 species, including three Israel hybrids). • Established then disappeared—species that Table 1 includes family and ordinal memberships have reproduced in the wild but later disap- of the species. We compared the number of peared from native habitats (one species). species from the four fish families with the most • Established as isolated or rare—species that introduced species worldwide (Cyprinidae, Cic- are reproducing in wild habitats but are either hlidae, Salmonidae, Characidae) (based on ‘‘Fish- rare in all the habitats they occupy or found Base’’) to the number of introduced species in only in one or a few isolated habitats (7 Israel from these families. World and Israeli species). proportions in these families did not differ (chi- • Established and common—species distributed squared = 2.33, P = 0.505; v2 goodness of fit test). in many habitats and common in at least some However species from the family Mugilidae (4 species, including one hybrid). constitute 14.6 percent (6 of 41) of the Israeli introduced fishes but only 1.47 percent (9 of 610) Table 1 lists the species and their status of introduced fishes worldwide. categories. In several cases reproduction in the Native geographic ranges of the fishes intro- wild or lack thereof was uncertain, and we duced to Israel are displayed in Table 1. The categorized the species according to available fishes come from different biogeographic regions knowledge. All species were divided into two (marine species are indicated in the table as ‘‘salt general categories: not established—those species water’’ - these species are introduced from the belonging to the first three categories (30 species); Israeli Mediterranean coast; see below). Fourteen and established—those species belonging to the of the 29 species (48 percent) that are not last two categories (11 species). introduced from saltwater habitats come from Table 2 shows the number of species in each either the Palearctic or Holoarctic regions. One status category for Israel and the entire world more species—the Redbelly tilapia (Tilapia (Welcomme 1988). Comparing the proportions of zillii)—was introduced within freshwater habitats species in each category between Israel and world in Israel. It was transported from the coastal plain data revealed significant differences (chi- for aquaculture purposes to pools south of the squared = 19.55, P = 2.11E-04; v2, goodness of Dead Sea and subsequently established popula- fit test). In the ‘‘Does not reproduce in the wild’’ tions in nearby springs. category Israel has more species than is expected We tabulated the purposes of the introductions from the world data (62.6% of the total chi- (Table 1).