HUMAN IMPACTS ON MARINE BIOTA

Author(s):  
CAROL M. LALLI ◽  
TIMOTHY R. PARSONS
Keyword(s):  
Author(s):  
Conrad J. Bahre ◽  
Luis Bourillón

Although many students of island biogeography consider the midriff islands one of the world’s last major refuges of pristine desert-island biota, humans have been a part of that ecosystem for possibly 10,000 years or more. Humans have long affected the terrestrial and inshore marine biota, but the most serious injuries they have caused apparently began in the mid- to late nineteenth century with the start of guano mining on Patos, Rasa, and San Pedro Mártir islands. Since then, most of the major human impacts affecting the Midriff are related to rapid population growth in northwestern Mexico and increasing demands for the Midriff’s fishery and tourist resources. This chapter offers both historical and ecological perspectives on the human occupancy of the Midriff, so that a cultural-historical foundation will be available for ecological studies in the region as well as for land-use planning and conservation. The Midriff, located between 28° and 29°45´N and 112° and 114°W, includes the coasts of Lower California and Sonora and 39 islands and islets. Tiburόn, with an area of 1223.53 km2 and a maximum elevation of 1219 m, and Ángel de la Guarda, with an area of 936.04 km2 and a maximum elevation of 1315 m, are among the largest and most mountainous islands of Mexico. The other major islands of the Midriff, in order of decreasing size, are San Esteban (40.72 km2), San Lorenzo (33.03 km2), Smith (Coronado) (9.13 km2), San Lorenzo Norte (Las Ánimas) (4.26 km2), San Pedro Mártir (2.9 km2), Mejía (2.26 km2), Partida Norte (1.36 km2), Dátil (Turner) (1.25 km2), Alcatraz (Tassne or Pelícano) (1.2 km2), Salsipuedes (1.16 km2), Estanque (Pond) (1.03 km2), Rasa (0.68 km2), and Patos (0.45 km2) (Murphy, unpublished data). The entire region is extremely arid, and Tiburón is the only island that has permanent potable water, found in a few springs or in tinajas, although several tinajas on Ángel de la Guarda may contain water for long periods. The only island permanently inhabited since initial European contact is Tiburón, the historic stronghold of the Seri Indians or Comcáac, once a seminomadic, nonagricultural, seafaring, hunting, fishing, and gathering people.


2022 ◽  
Vol 14 (2) ◽  
pp. 828
Author(s):  
Grigorios L. Kyriakopoulos ◽  
Miltiadis G. Zamparas ◽  
Vasileios C. Kapsalis

During the last decades, one of the most contentious environmental issues has been the investigation of the fate of microplastics (MPs) and detrimental consequences in natural and water resources worldwide. In this respect, it is critical research firstly to track the ways in which MPs are determined as key anthropogenic pollutants in terms of ecological risk and secondly to plan feasible policies under which the role of science and society in tackling this global issue in the future should be prioritized. In this study, a systematic theoretical, technical, and planning analysis was developed in alignment with a Scopus search deployed in the second half of the year 2021 and covering a wide chronological range (from 1970s onwards) and thematic contexts of analysis by using keywords and key phrases organized into two groups. The document results were graphically represented, revealing the main scientific focus of studies. Subsequently, our study investigated the quantitative assessment methods of MPs in marine environments, denoting the range of standard procedures applied for collecting and analyzing samples of water, bottom sediments, and coastal deposits. The technological part of the study includes the presentation of the relevant analytical techniques applied for MPs tracking and monitoring in water resources, determining the wide spectrum of plastic compounds traced. Of particular interest was the determination of environmental depletion and human implications caused, even by extremely low concentrations of MPs, for marine biota, posing potential risks to marine ecosystems, biodiversity, and food availability. Finally, the research proposed the challenges of actions needed to support scientific, industry, policy, and civil society communities to curb the ongoing flow of MPs and the toxic chemicals they contain into water resources, while rethinking the ways of plastics consumption by humanity.


Author(s):  
Sonny Tasidjawa ◽  
Stephanus V Mandagi ◽  
Ridwan Lasabuda

Bahoi village is located in West Likupang District of North Minahasa Regency. It is one of the villages that is included in the conservation network of North Sulawesi Province. A marine sanctuary has been established in this village in 2003 and it has been managed by local community, known as community-based marine sanctuary management, since then, this sanctuary has been in operation. As a small community-based marine protected area with lots of users, it requires an appropriate method to determine the Core Zone that allows an effective preservation of the marine biota. This is the driving factor of this study.  The purpose of this study is to examine the processes and output of determining the core zone of a Marine Sanctuary using a conventional method and Marxan Method. The conventional method is a simple method in determining a core zone such as using manta tow technique. While Marxan, it only requires input of data such as spatial and figures to generate information for determining the core zone. After comparing the processes of these two methods in the study site, it was found that Marxan method was more effective and more accurate with lower costs than the conventional one. In addition, the final decision of the core zone depended on the outcome of the village meetings when the conventional method was applied. This long process could be avoided when Marxan method was used. Therefore, it is highly recommended to use Marxan in determining core zones© Desa Bahoi terletak di Kecamatan Likupang Barat Kabupaten Minahasa Utara. Desa ini merupakan salah satu desa yang masuk dalam jejaringan kawasan konservasi di Provinsi Sulawesi Utara. Sebuah Daerah Perlindungan Laut telah didirikan di desa ini pada tahun 2003 dan dikelolah oleh masyarakat setempat, yang dikenal sebagai pengelolaan Daerah Perlindungan Laut Berbasis Masyarakat, sejak saat itu Daerah Perlindungan Laut ini telah beroperasi. Sebagai Daerah Perlindungan Laut Berbasis Masyarakat yang kecil namun memiliki banyak pengguna, diperlukan metode tepat yang akan menentukan Zona Inti yang memungkinkan pelestarian biota laut menjadi sangat efektif. Ini adalah faktor pendorong dari penelitian. Selanjutnya, tujuan dari penelitian ini adalah untuk mengkaji proses dan hasil penentuan zona inti Daerah Perlindungan Laut dengan menggunakan metode konvensional seperti survei manta tow dan marxan. Metode konvensional adalah metode sederhana dalam menentukan zona inti seperti teknik manta tow. Sedangkan marxan, hanya perlu memasukan data seperti spasial dan angka untuk menghasilkan informasi penentuan zona inti. Setelah membandingkan proses dari dua metode di lokasi penelitian, ditemukan bahwa metode marxan jauh lebih baik dari pada metode konvensional, karena lebih efektif, lebih akurat dengan biaya yang lebih rendah. Selain itu, keputusan akhir dari zona inti tergantung pada hasil rapat desa ketika metode konvensional diterapkan, proses panjang ini dapat dihindari jika metode marxan digunakan©


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