<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0717-7178</journal-id>
<journal-title><![CDATA[Investigaciones marinas]]></journal-title>
<abbrev-journal-title><![CDATA[Investig. mar.]]></abbrev-journal-title>
<issn>0717-7178</issn>
<publisher>
<publisher-name><![CDATA[Escuela de Ciencias del Mar <BR>Pontificia Universidad Católica de Valparaíso]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0717-71782007000200005</article-id>
<article-id pub-id-type="doi">10.4067/S0717-71782007000200005</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[An economic analysis of the Heterocarpus reedi and Cervimunida johni fisheries off northern-central Chile, from 1997 to 2000]]></article-title>
<article-title xml:lang="es"><![CDATA[Análisis económico de la pesquería de Hetercorpus reedi y Cervimunida johni en la zona centro norte de Chile, periodo 1997-2000]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Pérez]]></surname>
<given-names><![CDATA[Eduardo P]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
<xref ref-type="aff" rid="A02"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad Católica del Norte Facultad de Ciencias del Mar Departamento de Biología Marina]]></institution>
<addr-line><![CDATA[Coquimbo ]]></addr-line>
<country>Chile</country>
</aff>
<aff id="A02">
<institution><![CDATA[,Centro de Estudios Avanzados en Zonas Áridas (CEAZA)  ]]></institution>
<addr-line><![CDATA[La Serena ]]></addr-line>
<country>Chile</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>11</month>
<year>2007</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>11</month>
<year>2007</year>
</pub-date>
<volume>35</volume>
<numero>2</numero>
<fpage>45</fpage>
<lpage>52</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.cl/scielo.php?script=sci_arttext&amp;pid=S0717-71782007000200005&amp;lng=en&amp;nrm=iso&amp;tlng=en"></self-uri><self-uri xlink:href="http://www.scielo.cl/scielo.php?script=sci_abstract&amp;pid=S0717-71782007000200005&amp;lng=en&amp;nrm=iso&amp;tlng=en"></self-uri><self-uri xlink:href="http://www.scielo.cl/scielo.php?script=sci_pdf&amp;pid=S0717-71782007000200005&amp;lng=en&amp;nrm=iso&amp;tlng=en"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[The economic effects resulting from the diminishing catch per unit of effort (CPUE) in the nylon shrimp and squat lobster fishery off northern-central Chile from 1997 to 2000 were evaluated. A bio-technological simulation model was used that describes the physical and biological performance variables for the fishery. An economic submodel was incorporated to the original model in order to perform an integrated analysis of the crustacean fishery, including the catch and processing sub-sectors. The economic results, in conjunction with the data on catch and stock size, explained this fishery's dynamic off northern-central Chile during the study period. The total catch increased 21% between 1997 and 2000 and the final production increased 24%, but the quasi rent of the variable costs increased only 11%. The same period saw costs associated with fishing trips increase 117% and the total production cost increased 93%. The study results showed that part of the profits were lost due to the decreased biomass of both resources and the excessive increase in the average production costs, which were explained by the increased fishing trip costs. In order to obtain a better representation of the fishery's performance, economic references points should be incorporated to complement the traditional biological (biomass) and fishery (CPUE, catches) proxies]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Se analizó el efecto económico debido a la disminución de la captura por unidad de esfuerzo (CPUE) en la pesquería de camarón nailon y langostino amarillo en la zona norte y central de Chile durante el periodo 1997-2000. Se utilizó un modelo de simulación biológico-tecnológico que da cuenta de variables de desempeño físicas y biológicas. A este modelo se le incorporó un submodelo económico para realizar un análisis integrado de la pesquería de crustáceos que incluye el subsector de captura y procesamiento. Los resultados económicos obtenidos, sumados a los resultados de captura y de tamaño del stock permiten explicar la dinámica de esta pesquería en la zona centro-norte de Chile durante el período 1997-2000, donde la captura aumentó en 21%, la producción final aumentó en 24%, pero la cuasi renta de los costos variables aumentó sólo 11%. En este mismo período los costos por marea incrementaron 117% y el costo total de producción aumentó 93%. Los resultados mostraron que parte del beneficio económico se pierde debido a la disminución de la biomasa de ambos recursos y a un aumento excesivo en los costos medios de producción, que fueron explicados por el aumento en los costos de marea. Se recomienda incorporar puntos de referencia económicos en orden a tener una mejor representación del desempeño de la pesquería, como un complemento a los indicadores de desempeño biológicos (biomasa) y pesqueros (CPUE y captura) usados tradicionalmente]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[economics]]></kwd>
<kwd lng="en"><![CDATA[nylon shrimp]]></kwd>
<kwd lng="en"><![CDATA[squat lobster]]></kwd>
<kwd lng="en"><![CDATA[quasi rent]]></kwd>
<kwd lng="es"><![CDATA[Chile]]></kwd>
<kwd lng="es"><![CDATA[economía]]></kwd>
<kwd lng="es"><![CDATA[camarón nailon]]></kwd>
<kwd lng="es"><![CDATA[langostino amarillo]]></kwd>
<kwd lng="es"><![CDATA[cuasi renta]]></kwd>
<kwd lng="es"><![CDATA[Chile]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[  <table width="100%">   <tr>      <td width="3%">&nbsp;</td>     <td width="94%">           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">Invest. Mar.,          Valparaíso, 35(2): 45-52, 2007</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b><font size="4">An          economic analysis of the <i>Heterocarpus reedi </i>and <i>Cervimunida          johni </i>fisheries off northern-central Chile, from 1997 to 2000</font></b></font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b><font size="3">Análisis          económico de la pesquería de <i>Hetercorpus reedi y Cervimunida johni          </i>en la zona centro norte de Chile, periodo 1997-2000</font></b></font></p>           <p>&nbsp;</p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b>Eduardo          P. Pérez<sup>1,2</sup></b></font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><sup>1</sup>Universidad          Católica del Norte, Facultad de Ciencias del Mar, Departamento de Biología          Marina, Casilla 117, Coquimbo, Chile.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><sup>2</sup>Centro          de Estudios Avanzados en Zonas Áridas (CEAZA), La Serena, Chile.</font></p>       <hr size="1" noshade>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b>ABSTRACT.          </b>The economic effects resulting from the diminishing catch per unit          of effort (CPUE) in the nylon shrimp and squat lobster fishery off northern-central          Chile from 1997 to 2000 were evaluated. A bio-technological simulation          model was used that describes the physical and biological performance          variables for the fishery. An economic submodel was incorporated to the          original model in order to perform an integrated analysis of the crustacean          fishery, including the catch and processing sub-sectors. The economic          results, in conjunction with the data on catch and stock size, explained          this fishery's dynamic off northern-central Chile during the study period.          The total catch increased 21% between 1997 and 2000 and the final production          increased 24%, but the quasi rent of the variable costs increased only          11%. The same period saw costs associated with fishing trips increase          117% and the total production cost increased 93%. The study results showed          that part of the profits were lost due to the decreased biomass of both          resources and the excessive increase in the average production costs,          which were explained by the increased fishing trip costs. In order to          obtain a better representation of the fishery's performance, economic          references points should be incorporated to complement the traditional          biological (biomass) and fishery (CPUE, catches) proxies.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b>Key words:          </b>economics, nylon shrimp, squat lobster, quasi rent, Chile.</font></p>       <hr size="1" noshade>           ]]></body>
<body><![CDATA[<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b>RESUMEN.          </b>Se analizó el efecto económico debido a la disminución de la captura          por unidad de esfuerzo (CPUE) en la pesquería de camarón nailon y langostino          amarillo en la zona norte y central de Chile durante el periodo 1997-2000.          Se utilizó un modelo de simulación biológico-tecnológico que da cuenta          de variables de desempeño físicas y biológicas. A este modelo se le incorporó          un submodelo económico para realizar un análisis integrado de la pesquería          de crustáceos que incluye el subsector de captura y procesamiento. Los          resultados económicos obtenidos, sumados a los resultados de captura y          de tamaño del stock permiten explicar la dinámica de esta pesquería en          la zona centro-norte de Chile durante el período 1997-2000, donde la captura          aumentó en 21%, la producción final aumentó en 24%, pero la cuasi renta          de los costos variables aumentó sólo 11%. En este mismo período los costos          por marea incrementaron 117% y el costo total de producción aumentó 93%.          Los resultados mostraron que parte del beneficio económico se pierde debido          a la disminución de la biomasa de ambos recursos y a un aumento excesivo          en los costos medios de producción, que fueron explicados por el aumento          en los costos de marea. Se recomienda incorporar puntos de referencia          económicos en orden a tener una mejor representación del desempeño de          la pesquería, como un complemento a los indicadores de desempeño biológicos          (biomasa) y pesqueros (CPUE y captura) usados tradicionalmente.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b>Palabras          clave: </b>economía, camarón nailon, langostino amarillo, cuasi renta,          Chile.</font></p>       <hr size="1" noshade>           <p>&nbsp;</p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b><font size="3">INTRODUCTION</font></b></font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">Recently,          Pérez (2005) described the dynamics of biomass, catches, and catch per          unit of effort (CPUE, ton-trawl<sup>-1</sup>) for the <i>Heterocarpus          reedi </i>nylon shrimp fishery off northern Chile. The CPUE for both nylon          shrimp and squat lobster progressively decreased from 1997 to 2000 (SUBPESCA,          2005a, 2005b; Quiroz <i>et al.,</i>2005). An earlier work by Pérez (2003)          showed the same pattern for the squat lobster, <i>Cervi-munidajohni, </i>off          northern Chile. Since these fisheries are managed through a system of          a maximum catch limits (MCL) per vessel owner, with an annual global quota          equal to the total permissible catch (TPC), a decrease in the CPUE is          expected to imply an increase in the fishing effort (in number of trawls)          as a way to reach the TPC established for the season. Pérez (2003) described          a time limit for the daily number of trawls per vessel. Hence, the only          way to maintain the TPC levels is by increasing the fishing period at          sea, which could have economic consequences for the industry due to the          possible increase in operation costs. In extreme cases (i.e. open access),          the stock externalities caused by increased effort have been shown to          result in a complete loss of the income generated by a resource (Seijo          <i>et al., </i>1997).</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">In this work,          we analyze the bio-economic effect, mainly in terms of the increased catch          costs, of the decreased CPUE on the nylon shrimp and squat lobster fishery          off northern Chile between 1997 and 2000.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b><font size="3">MATERIALS          AND METHODS</font></b></font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">This study          was carried out off northern-central Chile (<a href="#fig1">Fig. 1</a>)          between September 1997 and August 2000. The analysis was based on the          bio-technological model developed for nylon shrimp <i>{Heterocarpus reedi)          </i>and squat lobster <i>(Cervimunida johni, Pleu-roncodes monodon) </i>(Pérez,          2003,2005). This model was fed data and information provided by the fishing          companies through the daily monitoring of the spatial and temporary dynamics          of effort and the CPUE (ton-trawl<sup>-1</sup>) displayed by the fleet          on nylon shrimp and squat lobster (<a href="#fig2">Fig. 2</a>, <a href="#fig3">3</a>).          An economic sub-model was incorporated into the original simulation model          in order to perform an integrated analysis of the fisheries (Sparre &amp;          Willmann, 1993) based on the information provided by the companies for          the same time period.</font>    <br>           <p align="center"><a name="fig1"></a>     ]]></body>
<body><![CDATA[<br>         <img src="/fbpe/img/imar/v35n2/fig06-01.jpg" width="600" height="423">        </p>           
<p align="center"><a name="fig2"></a>    <br>         <img src="/fbpe/img/imar/v35n2/fig06-02.jpg" width="600" height="415">        </p>           
<p align="center"><a name="fig3"></a>    <br>         <img src="/fbpe/img/imar/v35n2/fig06-03.jpg" width="600" height="416">        </p>           
<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">The results          were described on the basis of annual seasons that stretched from September          of one year to August of the next, according to the evaluation criterion          of the Subsecretaría de Pesca, Chile. The three analyzed fishing seasons          were called 97-98 (September 1997-August 1998), 98-99 (September 1998-August          1999), and 99-00 (September 1999-August 2000).</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">Off northern-central          Chile, the crustacean fishing industry is vertically integrated. In operational          terms, the companies define the basic unit as a three-day long fishing          trip. The costs of the fishing trip, processing, conversion factors, and          market price of the final product (both nylon shrimp and squat lobster)          are given in <a href="#tab1">Table 1</a>. In some cases, some companies          have to buy raw materials from other companies in order to meet their          stipulated export volumes. Although this practice is marginal, it is possible          to define an ex-vessel market price for each resource (<a href="#tab1">Table          1</a>).</font>    <br>           <p align="center"><a name="tab1"></a>    <br>         <img src="/fbpe/img/imar/v35n2/tb06-01.jpg" width="600" height="535">        </p>           
]]></body>
<body><![CDATA[<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">The fishing          trip costs were determined by calculating the number of fishing trips          per week <i>t. </i>By dividing the observed weekly catch by the average          weekly CPUE (ton-trawl<sup>-1</sup>), we get the total trawls per week.          Thus, the number of fishing trips can be obtained by dividing the total          number of trawls by the trawls per fishing trip. The total operational          cost per week for fishing trips <i>(CMJ </i>can be determined as:</font></p>           <p align="center"><img src="/fbpe/img/imar/v35n2/form06-01.jpg" width="200" height="34"></p>           
<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">where <i>NM          </i>is the number of fishing trips and <i>CoM </i>is the cost per fishing          trip. <a href="#tab1">Table 1</a> summarizes the items related to the          costs per fishing trip.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">There is          an additional cost in the fleet, which is a bonus (paid to the vessel's          captain and crew) that depends on the catch volume per species. Thus,          the fleet's total cost per week is the sum of the total fishing trip cost          plus the cost of the catch bonus per species<i> i</i> (CBP<sub>t,i</sub>).          In the processing plant phase, there is an additional cost derived from          the tailing process, which is calculated as a payment (<a href="#tab2">Table          2</a>) per kilo of the tailed species <i>(CD<sub>t,i</sub>). </i>The total          variable cost per fishing season <i>(CV</i>) is calculated as follows:</font></p>           <p align="center"><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><img src="/fbpe/img/imar/v35n2/form06-02.jpg" width="250" height="51"></font></p>           
<p align="center"><a name="tab2"></a>    <br>         <img src="/fbpe/img/imar/v35n2/tb06-02.jpg" width="600" height="256">        </p>           
<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">Finally,          the weekly total revenues (IT<sub>(</sub>) are calculated per species          according to the following equation:</font></p>           <p align="center"><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><img src="/fbpe/img/imar/v35n2/form06-03.jpg" width="200" height="53"></font></p>           
<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">where <i>p<sub>i</sub>          </i>and <i>Q<sub>i</sub>. </i>are the price per kilo and the kilos of          final product of species <i>i, </i>respectively. These are calculated          as:</font>    ]]></body>
<body><![CDATA[<br>           <p align="center"><img src="/fbpe/img/imar/v35n2/form06-04.jpg" width="200" height="40"></p>           
<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">where <i>C<sub>t,i</sub>          </i>is the catch of species <i>i </i>in week <i>t </i>and <i>fc<sub>i          </sub></i>is the conversion factor from raw material to final product          for species <i>i </i>(<a href="#tab1">Table 1</a>).</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">The quasi          rent of the variable costs for each week <i>tis </i>determined as:</font></p>           <p align="center"><img src="/fbpe/img/imar/v35n2/form06-05.jpg" width="250" height="35"></p>           
<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">(Seijo <i>et          al., </i>1997), so the quasi rent per fishing season is:</font></p>           <p align="center"><img src="/fbpe/img/imar/v35n2/form06-06.jpg" width="250" height="54"></p>           
<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">The total          quasi rent for the fishery, then, is the sum of the quasi rent generated          by both resources. The use of the quasi rent of the variable costs is          justified by the lack of consideration of all the fixed costs in the accounting          activities. Hence, the average production cost was calculated by dividing          the total cost among the kilos of final product for each resource.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">We must state          explicitly that this integrated analysis is valid within the domain of          distinctions that we can determine given certain limitations, a) Processing          plants not only process raw material from catches, but are also able to          process products other than those resulting from fishing. Thus, the domain          of validity is restricted to profits derived from the exploitation and          processing of crustaceans, b) Access to economic information on the companies          is a delicate matter, as it is considered to be strategic information.          Therefore, we only have available information about the cost per unit          of effort and the value of the product elaborated from the raw material.          Other fixed or variable costs of the land operations and administration          were not available for this study, so the analysis only includes costs          associated with the catch and the cost of tailing the product, c) Finally,          all the economic values mentioned in the results are expressed in constant          prices.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b><font size="3">RESULTS</font></b></font></p>           ]]></body>
<body><![CDATA[<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">Between the          first and the third season, the average production cost, i.e. the cost          per kilo of final product, increased for both resources (<a href="#fig4">Fig.          4a</a>). In the case of nylon shrimp, it increased 131.3%, from US $3.9          to US $4.2 kg<sup>-1</sup> (7.7%), whereas for squat lobster, it increased          from US $1.6 kg<sup>-1</sup> (97-98) to US $3.7 kg<sup>-1</sup> (99-00).</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">The quasi          rent from the variable costs (<a href="#fig4">Fig. 4b</a>) fluctuated          between US $ 11 and US $ 12.3 million dollars. Most of this was contributed          by the nylon shrimp fishery, which increased annually. On the other hand,          the quasi rent from squat lobster decreased from US $6 (97-98) to US $3          million dollars (99-00).</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">The nylon          shrimp catch (<a href="#fig4">Fig. 4c</a>) increased </font><font size="2" face="Verdana, Arial, Helvetica, sans-serif">110.5%,          from 2,653 tons in 97-98 to 5,585 tons in 99-00. The squat lobster catch,          however, decreased 20.7%, from 5,468 to 4,337 tons.</font>    <br>           <p align="center"><a name="fig4"></a>    <br>         <img src="/fbpe/img/imar/v35n2/fig06-04.jpg" width="600" height="628">        </p>           
<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">The total          number of fishing trips (<a href="#fig4">Fig. 4d</a>) increased for both          species between the first and the third season. Fishing trips to catch          squat lobster increased 106.5%, from 232 in 97-98 to 479 in 99-00, whereas          those for nylon shrimp catches increased 120%, from 644 to 1,417 in the          same fishing seasons. The increased number of fishing trips is reflected          in the total variable costs of this item (<a href="#fig4">Fig. 4e</a>).</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">Despite the          decrease in squat lobster plant pro</font><font size="2" face="Verdana, Arial, Helvetica, sans-serif">duction          (<a href="#fig4">Fig. 4f</a>), the total revenues increased (Fig. 10)          thanks to the increase in nylon shrimp production (<a href="#fig4">Fig.          4f</a>, <a href="#fig4">4g</a>). Nevertheless, this increase in the total          revenues were accompanied by an increment in the total variable costs          (fleet and plant, <a href="#fig4">Fig. 4h</a>). Thus, whereas the final          product increased 24% in quantity, from 1,196 tons in 97-98 to 1,483 tons          in 99-00, the total variable costs increased 92.8% (<a href="#fig4">Fig.          4h</a>). This increase in the variable costs maintained the quasi rent          at the level of US $ 11 million for the three seasons (<a href="#fig4">Fig.          4a</a>) despite the increased nylon shrimp catch and production.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b><font size="3">DISCUSSION</font></b></font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">The economic          results, in conjunction with the data on catch and stock size (Pérez,          2003,2005), allow us to explain the benthic crustacean fishery dynamics          off northern-central Chile from 1997 to 2000 and the consequences observed          later.</font></p>           ]]></body>
<body><![CDATA[<p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">As of 1999,          the crustacean fishery experienced a difficult period off northern-central          Chile (SUBPESCA, 2005a, 2005b) because the TPC for the nylon shrimp fishery          decreased throughout the area from 10,000 tons in 1997 to 8,300 tons in          1998 and then dropped drastically from 7,900 tons in 1999 to 4,000 tons          in 2000. In other words, in a four-year period, the TPC decreased 60%.          In the case of the squat lobster fishery in this same region, the TPC          decreased from 6,000 tons in 1998 to 4,000 tons in 2000, that is, by 33%.          This reduction in the TPC resulted in a substantial decline in the activities          of fleets and plants. In 2002, some companies shut down and jobs were          lost due to the social importance of this fishery in the catch and processing          centers.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">The behavior          of the different performance variables for this period is consistent with          the problems the fishery experienced in 2001 and 2002. The lower biomass          of both resources (SUBPESCA, 2003, 2005a, 2005b; Pérez, 2003, 2005; Quiroz          <i>et al.,</i>2005) was consistent with the increase in average production          costs due to the decline in the CPUE (Pérez, 2003,2005), the need to increase          the number of fishing trips, and costs associated with these trips. For          example, the catch increased 21 % between 1997 and 2000 and the final          production increased 24%, whereas the quasi rent of variable costs increased          only 11%. In the same period, the fishing trip costs increased 117% and          the total production cost increased 93%. At the same time, the nylon shrimp          biomass decreased 54% (Pérez, 2005) and the squat </font><font size="2" face="Verdana, Arial, Helvetica, sans-serif">lobster          biomass decreased 67% (Pérez, 2003). The decrease in biomass, followed          by a lower CPUE (SUBPESCA, 2003, 2005a, 2005b; Pérez 2003, 2005; Quiroz          <i>et al., </i>2005), forced companies to make a greater effort in terms          of the number of fishing trips, which caused an important increase in          the production costs with the consequent loss of the expected profit.          If the fixed costs related to the fleet, processing, and administration          are considered, the economic benefits would decrease even more significantly.          This result is consistent with the prediction of Seijo <i>et al. </i>(1997),          in the sense that an extraction quota system, even if it can protect the          resource biomass, results in the loss of the surplus benefit derived from          the exploitation.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif">In this context,          economic reference points are necessary to provide a better representation          of the fishery performance (Seijo &amp; Caddy, 2000) complementary to          the commonly used biological (biomass) and fishery (CPUE, catch) performance          proxies (SUBPESCA, 2005a, 2005b). Moreover, the need arises to evaluate          the bio-economic effects of administrative measures in the short term          on the crustacean fishery in conjunction with the management practices          within the companies. The results showed that part of the profits that          could be generated by the resource are lost due to the combined effect          of the biomass decrease in both resources and the excessive increase in          the average production costs, which can be explained by the rise in the          fishing effort costs in terms of the number of fishing trips.</font></p>           <p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b><font size="3">REFERENCES</font></b></font></p>           <!-- ref --><p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b>Pérez,          E.P. 2003. </b>Análisis bio-económico de la pesquería de crustáceos en          la plataforma centro-norte de Chile. Tesis de Doctorado en Ciencias. 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Ser, Fisheries, 1: 186 pp.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scieloOrg/php/reflinks.php?refpid=S0717-7178200700020000500006&pid=S0717-71782007000200005&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');"></a>&#160;]<!-- end-ref --><!-- ref --><p><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><b>Subsecretaría          de Pesca (SUBPESCA). 2003. </b>Cuota global anual de captura de camarón          nailon entre la II y la VIII Región, año 2004. Informe Técnico de Pesca          (R. 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