Spatial and temporal occurrence of fin whales (Balaenoptera physalus) and euphausiids (Nyctiphanes simplex) in the Ballenas Channel, Gulf of California, Mexico
Fin whales (Balaenoptera physalus) are observed year-round in the Ballenas Channel and Bahía de los Ángeles region, Gulf of California, where their main food item is the euphausiid Nyctiphanes simplex. This investigation was designed under the hypothesis that the spatial and temporal occurrence of...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Universidad Autónoma de Baja California
2015-06-01
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| Series: | Ciencias Marinas |
| Online Access: | https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/2497 |
| _version_ | 1797279529824157696 |
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| author | Paloma Ladrón-de-Guevara Gisela Heckel Bertha E Lavaniegos |
| author_facet | Paloma Ladrón-de-Guevara Gisela Heckel Bertha E Lavaniegos |
| author_sort | Paloma Ladrón-de-Guevara |
| collection | DOAJ |
| description |
Fin whales (Balaenoptera physalus) are observed year-round in the Ballenas Channel and Bahía de los Ángeles region, Gulf of California, where their main food item is the euphausiid Nyctiphanes simplex. This investigation was designed under the hypothesis that the spatial and temporal occurrence of whales and euphausiids coincides. The aim was to establish the geographic, seasonal, and interannual changes in the abundance of the fin whale and its main prey in the region during 2003 and 2004. Four field trips were carried out per year. Surveys to search for whales and carry out horizontal surface tows were conducted from small boats. Fin whales and euphausiids were mainly observed off the coast of Baja California and in the southern Ballenas Channel. Their abundance varied significantly from one season to another in both years. The highest relative abundance of whales occurred in July (warm season), followed by June (cold–warm transition period) and March–April (cold season), and the lowest in October (late warm season). Euphausiid abundance was significantly higher in June (cold–warm transition period), followed by July (warm season). There was no direct correlation between weekly abundances of both species, probably because whale peak abundance occurred four weeks later than euphausiid peak abundance. Fin whale relative abundance was significantly higher in 2004 than in 2003 (2.22 and 0.46 whales h–1, respectively), but euphausiid abundance remained almost the same (geometric means 255 and 174 ind/1000 m3). Even though there was no weekly correlation between both species, their geographic distribution did overlap.
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| first_indexed | 2024-03-07T16:27:05Z |
| format | Article |
| id | doaj.art-e9508ff4a99e44c0bd700c339de45aa0 |
| institution | Directory Open Access Journal |
| issn | 0185-3880 2395-9053 |
| language | English |
| last_indexed | 2024-03-07T16:27:05Z |
| publishDate | 2015-06-01 |
| publisher | Universidad Autónoma de Baja California |
| record_format | Article |
| series | Ciencias Marinas |
| spelling | doaj.art-e9508ff4a99e44c0bd700c339de45aa02024-03-03T17:49:14ZengUniversidad Autónoma de Baja CaliforniaCiencias Marinas0185-38802395-90532015-06-0141210.7773/cm.v41i2.2497Spatial and temporal occurrence of fin whales (Balaenoptera physalus) and euphausiids (Nyctiphanes simplex) in the Ballenas Channel, Gulf of California, MexicoPaloma Ladrón-de-Guevara0Gisela Heckel1Bertha E Lavaniegos2Centro de Investigación Científica y de Educación Superior de EnsenadaCentro de Investigación Científica y de Educación Superior de EnsenadaCentro de Investigación Científica y de Educación Superior de Ensenada Fin whales (Balaenoptera physalus) are observed year-round in the Ballenas Channel and Bahía de los Ángeles region, Gulf of California, where their main food item is the euphausiid Nyctiphanes simplex. This investigation was designed under the hypothesis that the spatial and temporal occurrence of whales and euphausiids coincides. The aim was to establish the geographic, seasonal, and interannual changes in the abundance of the fin whale and its main prey in the region during 2003 and 2004. Four field trips were carried out per year. Surveys to search for whales and carry out horizontal surface tows were conducted from small boats. Fin whales and euphausiids were mainly observed off the coast of Baja California and in the southern Ballenas Channel. Their abundance varied significantly from one season to another in both years. The highest relative abundance of whales occurred in July (warm season), followed by June (cold–warm transition period) and March–April (cold season), and the lowest in October (late warm season). Euphausiid abundance was significantly higher in June (cold–warm transition period), followed by July (warm season). There was no direct correlation between weekly abundances of both species, probably because whale peak abundance occurred four weeks later than euphausiid peak abundance. Fin whale relative abundance was significantly higher in 2004 than in 2003 (2.22 and 0.46 whales h–1, respectively), but euphausiid abundance remained almost the same (geometric means 255 and 174 ind/1000 m3). Even though there was no weekly correlation between both species, their geographic distribution did overlap. https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/2497 |
| spellingShingle | Paloma Ladrón-de-Guevara Gisela Heckel Bertha E Lavaniegos Spatial and temporal occurrence of fin whales (Balaenoptera physalus) and euphausiids (Nyctiphanes simplex) in the Ballenas Channel, Gulf of California, Mexico Ciencias Marinas |
| title | Spatial and temporal occurrence of fin whales (Balaenoptera physalus) and euphausiids (Nyctiphanes simplex) in the Ballenas Channel, Gulf of California, Mexico |
| title_full | Spatial and temporal occurrence of fin whales (Balaenoptera physalus) and euphausiids (Nyctiphanes simplex) in the Ballenas Channel, Gulf of California, Mexico |
| title_fullStr | Spatial and temporal occurrence of fin whales (Balaenoptera physalus) and euphausiids (Nyctiphanes simplex) in the Ballenas Channel, Gulf of California, Mexico |
| title_full_unstemmed | Spatial and temporal occurrence of fin whales (Balaenoptera physalus) and euphausiids (Nyctiphanes simplex) in the Ballenas Channel, Gulf of California, Mexico |
| title_short | Spatial and temporal occurrence of fin whales (Balaenoptera physalus) and euphausiids (Nyctiphanes simplex) in the Ballenas Channel, Gulf of California, Mexico |
| title_sort | spatial and temporal occurrence of fin whales balaenoptera physalus and euphausiids nyctiphanes simplex in the ballenas channel gulf of california mexico |
| url | https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/2497 |
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