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LIBRO DIVERSIDAD DE PECES EN ECUADOR
Abstract and Figures
Esta serie especial de ictiología ecuatoriana, número I, es una contribución de la Red Ecuatoriana de Ictiología (REI) que busca trasmitir información científica para que esté al alcance de todos, accesible a un público amplio. Así, gestores, manejadores y tomadores de decisiones podrán contar con información sobre un recurso natural del que poco se habla, pero que es explotado (y sobreexplotado), porque poco se sabe.
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• Public aquaria globally display numerous threatened fish species captured from wild populations. Potential impacts of harvests are rarely evaluated despite the need for improved management and conservation practices.
• Sawfishes (Family Pristiidae) are one of the world's most at‐risk fish families. Most commonly displayed (30+ wild caught individuals) is the Critically Endangered largetooth sawfish, Pristis pristis.
• Two Australian aquaria release captive P. pristis to the wild as they outgrow displays, intending to offset impacts of the original harvests. The fate of released sawfish is unknown.
• Using acoustic telemetry, the behaviour (rates of movement, patterns of habitat use) and survival of aquarium released sawfish (n = 5) were compared to a control group of wild sawfish (n = 5).
• Aquarium sawfish had reduced rates of movement, were more sedentary, and occupied smaller activity spaces than wild sawfish; but diel activity and habitat use patterns were similar.
• Collectively, mortality was high. Two aquarium sawfish survived to the end of the monitoring period (391 days and 117 days, respectively), and no wild sawfish survived. The mean duration of survival for aquarium and wild sawfish was 157 and 58 days, respectively.
• Whilst captivity affected behaviours, the lower mortality rates of aquarium sawfish indicates that releases may partially offset the impact of the original harvest. Further data are required to investigate potential long‐term ecological impacts.
• If P. pristis are to be used for aquarium displays, the best conservation outcomes could be achieved by harvesting in the first year of life when natural mortality is highest, followed by release into the freshwater reaches of the natal river where predation risk may be minimized. Size on release should be less than ~2,800 mm total length to allow for migration from the river system as part of their natural life cycle.
The composition and landings of sharks were determined based on the collected data in 2012 from the monitoring of artisanal fishing fleet directed to the fishery of big pelagic fishes carried out by the staff of Instituto Nacional de Pesca. The sharks landing was estimated in 9361.0 tonnes which representes an increase of 2.7% compared to 2011 but a decrease of 15.5% compared to 2010. Alopias pelagicus and Prionace glauca were species commonly landed and Manta was the most representative fishing port in terms of volumes landed. These shark species were captured as bycatch from the artisanal fleet that captures tunas, weevil and sword using coarse longline. Regarding the sexual maturity of shark species, a high quantitaty of immature individuals were registered in the landings of C. falciformis, S. zygaena and I. oxyrinchus, while A. pelagicus and P. glauca had a different behavior when registering more than 50% of mature organisms. The sharks catch areas were located mainly southwest of the Galapagos Islands in the case of the fleet of vessels that catch tuna, weevil and swordfish and in international waters between 00°02’ N and 12°00’ S for dorado.
The monotypic genus Landonia Eigenmann & Henn, 1914 was only known from its type locality in western Ecuadorian drainages. Recent collections revealed the presence of Landonia latidens Eigenmann & Henn, 1914 in Chira and Piura river basins in Peru. Thus, the distribution of this species is extended, constituting the southernmost record of the species.
A short-term projection model is developed to assess and monitor potential future fish demand and supply gaps at the country (nearly 200 countries or territories), regional (about 40 country groups), and global levels for nine species groups. Salient results at the global, regional and country levels are presented in the main text. Key results for all countries and all the nine species groups (including both standard and conservative projections) are documented in the appendix. The results indicate that: (i) if fish prices and consumer preferences remain the same, income growth would drive world per capita fish demand up from 20 kg/year in the mid-2010s to 25 kg/year in the early 2020s (or 23 kg/year under the conservative projection); (ii) the income-driven per capita fish demand hike, combined with population growth, would drive world fish demand up by 47 million tonnes (or 31 million tonnes under the conservative projection); (iii) the 19-million-tonne fish supply growth generated by the trend growth of world aquaculture production would cover only 40 percent of the projected demand growth (or 62 percent of the conservative projection), leaving a fish demand-supply gap of 28 million tonnes (or 16 million tonnes under the conservative projection) in the early 2020s; (iv) the demand-supply gap for shellfish (i.e. crustaceans and molluscs) would be bigger than that for finfish – they would account for, respectively, 55 percent and 45 percent of the 28-million-tonne fish demand-supply gap; (v) while world aquaculture production following its recent trend would grow 4.5 percent annually from the mid2010s to the early 2020s, it would take a 9.9 percent annual growth (or 6.9 percent under the conservative projection) to fill the world fish demand-supply gap in the early 2020s; (vi) the trend aquaculture growth in only 17 countries (or 24 countries under the conservative projection) would be sufficient to cover the demand growth driven by population and income growth; excess demand is expected to occur in 170 countries (or 163 countries under the conservative projection); and (vii) should the world aquaculture production fall short of the required annual growth rate (i.e. 9.9 percent or 6.9 percent under the standard or conservative projection), and assuming world capture fisheries production would remain at the current level, the world fish price would have to increase to reduce fish demand in order to clear the market (i.e. no demand-supply gap). Results generated by the short-term projection model are useful for policymaking, development aids, business or investment planning, and other decision-making by various stakeholders in aquaculture and fisheries. They are a complement to and can potentially enhance the understanding of the results of more sophisticated forecasting models such as the OECD-FAO Fish Model and the World Bank-IFPRI-FAO Fish to 2030 model.
El presente trabajo se desarrolló como complemento al componente de restauración ecológica contemplado dentro del marco de acción del Plan de Gestión Ambiental del FONAG (Fondo para la conservación del Agua), institución adscrita al Municipio de Quito. El documento forma parte de una línea base de información que gira en torno a la construcción de un escenario adecuado para emprender actividades de restauración ecológica fluvial, en los ambientes en los que ésta fuera necesaria. A nivel municipal es importante que las consideraciones que aquí se discuten así como las iniciativas de restauración ecológica fluvial se inserten como un componente más dentro de los planes de gestión ambiental que cada gobierno local (GAD) tenga que emprender en el territorio de su jurisdicción, y se lo aborde como un elemento que requiere un permanente seguimiento y monitoreo para detectar oportunamente los cambios en la calidad y cantidad del agua que se puedan presentar en una determinada zona y se puedan tomar las acciones de manejo que correspondan.
The feeding habits of Makaira nigricans, Kajikia audax, Istiophorus platypterus (Istiophoridae), and Xiphias gladius (Xiphiidae) in the southeast Pacific Ocean were examined in Manta and Santa Rosa, Ecuador. This study describes the diets of these billfish species, evaluates dietary differences between species, and assesses seasonal differences in diet. A total of 274 M. nigricans, 321 K. audax, 267 I. platypterus, and 252 X. gladius were collected between February 2014 and April 2015. The scombrid Auxis spp. was the most important prey for M. nigricans, K. audax and I. platypterus, while the squid Dosidicus gigas was the most important prey for X. gladius. The results of the ANOSIM confirmed significant differences in feeding habits between the members of the family Istiophoridae and X. gladius. Seasonal differences for I. platypterus also were observed. Billfishes are specialist consumers with a narrow niche breadth (B a: M. nigricans and K. audax=0.1, I. platypterus=0.05, and X. gladius=0.04).
Available online under
http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp
After more than fifteen years of existence, the R package ape has continuously grown its contents, and has been used by a growing community of users. The release of version 5.0 has marked a leap towards a modern software for evolutionary analyses. Efforts have been put to improve efficiency, flexibility, support for 'big data' (R's long vectors), ease of use, and quality check before a new release. These changes will hopefully make ape a useful software for the study of biodiversity and evolution in a context of increasing data quantity.
Availability:
ape is distributed through the Comprehensive R Archive Network: http://cran.r-project.org/package=apeFurther information may be found athttp://ape-package.ird.fr/.