Abstract—Ecotoxicology has focused

Abstract—Ecotoxicology has focused almost exclusively on countries and ecosystems in temperate zones. Tropical ecosystems, which combined contain as much as 75% of the global biodiversity, have been neglected. Tropical ecosystems are under increasing threat of development and habitat degradation from population growth and urbanization, agricultural expansion, deforestation, and mining. Some of these activities also lead to the release of toxic substances into the environment. Little research in ecotoxicology has been carried out in tropical environments. Techniques and procedures developed for temperate environments are often applied, even though physical and chemical environmental parameters in the tropics can be very different. Most research has focused on water quality and aquatic toxicology. The regulatory environment also varies among countries. We present a review of the literature on tropical ecotoxicology, with an emphasis on Latin America and the Caribbean. We also address priority areas for immediate research in the tropics. These include large-scale agricultural activities, especially banana, pineapple, and soybean farming, and gold mining with the associated heavy use of mercury. We outline the special issues that must be addressed as the field of tropical ecotoxicology progresses.

Keywords—Tropical ecotoxicology Rain forest Pesticides Neotropical migrants Biodiversity




INTRODUCTION

Tropical terrestrial and freshwater ecosystems cover only
25.7% of the land area on the surface of the Earth [1], but this area generates nearly 60% of the primary productivity of the planet [1] and contains approx. two-thirds of all the known species of vascular plants [2]. The number of species of most major taxa increases with decreasing latitude [3] (Table 1); thus, tropical ecosystems harbor the bulk of the world’s spe- cies. Some estimate that more than two-thirds of the world’s flora and fauna is found in the tropics [4].
Concern over the amount of environmental degradation in tropical ecosystems has increased dramatically over the past decade. The 1992 Earth Summit in Rio de Janeiro, Brazil, further catalyzed interest in the tropics, and the 1994
Summit of the Americas in Miami, Florida, USA, addressed hemispheric concerns over environmental problems in nations with tropical environments. A document prepared for the Miami summit presented examples of innovative approaches to sustainable development and conser vation in the tropics [5].
Innovative approaches are indeed necessary because tropical ecosystems are disappearing at an alarming rate (Table 2). Average annual deforestation between 1981 and 1985 in the Amazon Basin alone totaled 32,500 km2 year, an area equiv- alent to the U.S. states of Massachusetts and Connecticut com- bined [6]. Moreover, the annual deforestation rates of the coun- tries of the Amazon Basin (Table 2) are far less than those observed in other nations such as Thailand (2.7.%), Costa Rica (4.0%), and Nigeria (5.0%) [7].
Although deforestation is the most direct threat to tropical biodiversity, tropical ecosystems are currently threatened by

* To whom correspondence may be addressed. The current address of Thomas Lacher is Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843–2258, USA.

other human activities as well. Little research has been done on the impact of contaminants on tropical ecosystems, yet, considering research conducted in temperate regions, these compounds have potentially large effects [8]. In addition, trop- ical ecosystems are more poorly studied than temperate eco- systems, and the physical and chemical variables that affect biotic processes are different. We present an introduction to tropical ecosystems with a brief review of important environ- mental impacts and contaminant issues. We close this report with recommendations for applying the principles of environ- mental toxicology to the different ecological, sociological, and economic situations that are encountered in developing tropical countries.

The extent and nature of the tropics
Tropical environments differ ecologically from temperate zone habitats in physical, chemical, and biological attributes. Tropical environments occur between approx. 258 north and
258 south of the equator and are characterized by warm tem- peratures with little or no seasonality and heavy precipitation during at least part of the year [9] (Fig. 1). The tropics can be broadly classified into six major habitat types: tropical rain forests, tropical dry forests, tropical savannas, tropical wet- lands, tropical freshwater systems, and tropical marine envi- ronments [10] (Table 3).
Throughout the tropics, combinations of temperature and precipitation are encountered that do not exist in temperate regions. Our understanding of the fate and transport of envi- ronmental contaminants in northern latitudes has little appli- cability in the tropics [11]. In addition, biological diversity in the tropics is substantially higher than in temperate zones, and the number of species potentially affected by any given com- pound is also greater. Many taxa are poorly known, so little or nothing has been published on even the most fundamental aspects of their biology. New species are continually being


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Abstrak — Ecotoxicology telah berfokus hampir secara eksklusif pada negara-negara dan ekosistem di zona beriklim sedang. Ekosistem tropika yang dikombinasikan berisi sebanyak 75% keanekaragaman hayati global, telah diabaikan. Ekosistem tropika yang berada di bawah meningkatkan ancaman degradasi pengembangan dan penyebaran dari pertumbuhan penduduk dan urbanisasi, perluasan areal pertanian, deforestasi, dan pertambangan. Beberapa kegiatan ini juga menyebabkan rilis zat beracun ke lingkungan. Riset kecil di ecotoxicology telah dilakukan di lingkungan tropis. Teknik dan prosedur yang dikembangkan untuk iklim lingkungan sering diterapkan, meskipun parameter fisik dan kimia lingkungan hidup di daerah tropis bisa sangat berbeda. Kebanyakan penelitian telah difokuskan pada kualitas air dan Toksikologi akuatik. Lingkungan peraturan juga bervariasi antara negara-negara. Kami hadir review di dalam literatur pada ecotoxicology tropis, dengan penekanan pada Amerika Latin dan Karibia. Kami juga alamat area prioritas untuk penelitian langsung di daerah tropis. Ini termasuk kegiatan pertanian skala besar, terutama pisang, nanas, dan kedelai pertanian dan pertambangan emas dengan menggunakan berat terkait Merkurius. Kami menjelaskan masalah khusus yang harus diatasi sebagai bidang tropis ecotoxicology berlangsung.Kata kunci-ecotoxicology tropis hutan hujan pestisida salah migran keanekaragaman hayati PENDAHULUANTropis terestrial dan air tawar ekosistem menutupi hanya25,7% daratan di permukaan bumi [1], tapi daerah ini menghasilkan hampir 60% dari produktivitas utama planet [1] dan mengandung sekitar dua-pertiga dari semua spesies tanaman vaskuler [2]. Jumlah spesies taksa sebagian besar meningkat dengan penurunan lintang [3] (Tabel 1); dengan demikian, ekosistem tropika pelabuhan sebagian besar dunia spe-cies. Beberapa memperkirakan bahwa lebih dari dua-pertiga dari flora dan fauna di dunia terdapat di daerah tropis [4].Keprihatinan atas jumlah degradasi lingkungan di ekosistem tropika telah meningkat secara dramatis selama dekade terakhir. Pertemuan bumi di Rio de Janeiro, Brazil, lebih lanjut dikatalisasi menarik di daerah tropis, dan tahun 1994KTT Amerika di Miami, Florida, USA, dibahas melintang keprihatinan atas masalah lingkungan di negara-negara dengan lingkungan tropis. Sebuah dokumen yang disiapkan untuk KTT Miami disajikan contoh dari pendekatan inovatif untuk berkelanjutan pembangunan dan conser vation di daerah tropis [5].Innovative approaches are indeed necessary because tropical ecosystems are disappearing at an alarming rate (Table 2). Average annual deforestation between 1981 and 1985 in the Amazon Basin alone totaled 32,500 km2 year, an area equiv- alent to the U.S. states of Massachusetts and Connecticut com- bined [6]. Moreover, the annual deforestation rates of the coun- tries of the Amazon Basin (Table 2) are far less than those observed in other nations such as Thailand (2.7.%), Costa Rica (4.0%), and Nigeria (5.0%) [7].Although deforestation is the most direct threat to tropical biodiversity, tropical ecosystems are currently threatened by* To whom correspondence may be addressed. The current address of Thomas Lacher is Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843–2258, USA. other human activities as well. Little research has been done on the impact of contaminants on tropical ecosystems, yet, considering research conducted in temperate regions, these compounds have potentially large effects [8]. In addition, trop- ical ecosystems are more poorly studied than temperate eco- systems, and the physical and chemical variables that affect biotic processes are different. We present an introduction to tropical ecosystems with a brief review of important environ- mental impacts and contaminant issues. We close this report with recommendations for applying the principles of environ- mental toxicology to the different ecological, sociological, and economic situations that are encountered in developing tropical countries.Batas dan alam tropisLingkungan tropis berbeda ekologis dari zona iklim sedang habitat di atribut fisik, kimia, dan biologi. Lingkungan tropis terjadi antara kira-kira 258 Utara dan258 selatan khatulistiwa dan dicirikan oleh tem-peratures hangat dengan sedikit atau tidak ada musiman dan berat hujan selama setidaknya sebagian dari tahun [9] (Fig. 1). Daerah tropis secara luas dapat digolongkan ke dalam enam jenis habitat utama: hutan hujan tropis, hutan tropis yang kering, Sabana tropis, tropis basah-tanah, sistem air tawar tropis dan tropis laut tentang konsep didaktik matematika-ronments [10] (Tabel 3).Di daerah tropis, kombinasi dari suhu dan curah hujan ditemui yang tidak ada di daerah beriklim. Pemahaman kita tentang nasib dan transportasi tentang konsep didaktik matematika-ronmental kontaminan dalam lintang utara memiliki aplikasi-cability kecil di daerah tropis [11]. Selain itu, keanekaragaman hayati di daerah tropis substansial lebih tinggi dari di zona beriklim sedang, dan jumlah spesies yang berpotensi terkena dampak apapun diberikan com-pon juga lebih besar. Banyak taksa buruk diketahui, begitu sedikit atau tidak ada telah diterbitkan pada aspek-aspek yang bahkan paling mendasar biologi mereka. Spesies baru terus-menerus sedang 100