Posted on 06 February 2013 by Nazca admin
Why investigate Spondylus?
We are currently investigating the ecology and population dynamics of the bivalve genus Spondylus, also known as “spiny oysters”. The shells are famous for their beauty among collectors worldwide. Visitors of Ecuador have surely seen the amazing shells, either found clean and polished entirely or the beautiful jewellery that is made out of it, both found widely distributed in shops and on local markets. Very few visitors are probably aware that these slow-growing animals faced a heavy fishery pressure during the last decade and are nowadays a more and more disappearing resource. The fishery on Spondylus is still not regulated and consequently stocks appear to be severely overexploited. A detailed study of the ecology and population dynamics of Spondylus species is therefore urgently required to provide the information necessary for a sustainable management and thus protection of this ecologically and economically valuable resource.
History
The demand for Spondylus shells to manufacture the famous Spondylus jewellry severely threatens the populations of this slow-growing animalLa demanda de conchas de Spondylus para manufacturar la famosa joyería de Spondylus amenaza severamente las poblaciones de este animal de lento crecimiento
Typical Spondylus jewellry, using the wonderful colours of the small ring along the shell ends Típica joyería de Spondylus. Se aprovechan los bellos colores del estrecho anillo que se encuentra a lo largo del borde de las valvas
A fishermen can collect some 400-500 shells within 2 or 3 days of diving only, but the bivalve is becoming more and more scarce Un pescador puede llegar a recoger entre 400 y 500 conchas en solo 2 ó 3 días, pero este animal cada vez es más escaso
Spondylus serves as a host for a wide variety of epibiontsLos Spondylus sirven como huéspedes de una gran variedad de epibiontes.
Living Spondylus in a natural habitat. The arrow points at the gap between the two valves which sometimes is the only difference between the bivalve and a well overgrown stoneSpondylus vivo en su hábitat natural. La flecha indica el espacio entre las dos valvas, que a veces es la única diferencia a simple vista entre este bivalvo y una roca
Spondylus calcifer from the Ayangue areaSpondylus calcifer del área de Ayangue
These relatively “young” specimens are sold intact, as they still display the beautiful spines that disappear later in lifeEstos especímenes relativamente “jóvenes” se venden intactos, ya que aún conservan sus bellas espinas, que desaparecen con la edad
Spondylus princeps features a small attachment area, whereas Spondylus calcifer can be found attached to boulders and rocks with the whole left valve Spondylus princeps tiene una área de anclaje muy pequeña, mientras que Spondylus calcifer puede encontrarse adherido a grandes rocas usando todo el área de su valva izquierda
A typical Spondylus princeps with spinesTípico Spondylus princeps con sus características espinas
Belonging to the class of Bivalvia, the family Spondylidae (Gray, 1826) consists of only one genus: Spondylus (Linnaeus, 1758) with current estimates of different living species between 70 and 80, many of them under scientific revision. This family is closely related to the family Pectinidae (Scallops) with whom they share the complex eyes around the mantle and a relatively well developed nervous system. Spondylus is usually cemented to the substrate instead of using a byssus. Despite their abundance in the tropical oceans of the world, very little is known about basic biology and ecology of Spondylidae.
Three species are found along the coast of Ecuador, Spondylus calcifer, S. princeps and S. leucacanthus. Their large and magnificent shells have a long history in South American culture as ceremonial offerings and currency. A lively community of anthropologists is exploring and discussing the importance that Spondylus featured in South America during Valdivian and Incan times. Nowadays, Spondylus is again of significant commercial value in Ecuador regarding handicraft (jewellery) and alimentation.
Further investigations
We are also investigating the suitability of Spondylus shells as archives of long-term environmental variability. As in many bivalves, Spondylus shells display growth rings that are formed due to changes in environmental parameters such as water temperature, salinity, depth and light which influence the availability of food and therefore the metabolism and the growth of the animal. Owing to the presumed longevity of Spondylus, their shells may serve as archives of long-term environmental variability, i.e. its morphological and biogeochemical properties may reflect the influence of large-scale climate phenomena like ENSO (El Niño Southern Oscillation). The eastern tropical pacific is a key climate sector and calcifying marine organisms such as bivalves can provide high-resolution records of environmental parameters.
More Information:
Alfred Wegener Institute for Polar and Marine Research
Posted on 06 February 2013 by Nazca admin
The Pacific Ocean off of Ecuador encompasses important habitats for 27 marine mammal species and the Amazon basin is home to otters, manatees, and 2 species of dolphin. Since 1996, Nazca Institute researchers, in cooperation with foreign NGO’s such as Yaqu Pacha, have been studying the population biology, behaviour and conservation issues regarding the marine and aquatic mammals of Ecuador.
The Ecuadorian coastal habitats, especially in the provinces of Manabí and Esmeraldas, are preferred breeding grounds of the South Eastern Pacific Humpback whale population. From June to October, we have accompanied the whales every year since 1996 to monitor population size, distribution and the impact of whale watching tourism on their natural behaviour. Since 2000 have worked in close cooperation with fishermen in Esmeraldas, combining whale watching with our normal research activities.
Breeding SeasonTemporada Reproductiva
During the breeding season from June to September, humpback males breach to attract females, while receptive females call the males slapping their flippers on the surfaceDurante la temporada de reproducción, de junio a septiembre, los machos de las ballenas jorobadas ???? para atraer a las hembras, mientras que las hembras receptivas llaman a los machos golpeando sus aletas contra la superficie del agua
Humpback whales can be individually identified by their fluke patterns. By now, Nazca scientists identified more than 400 whales in the breeding grounds off Esmeraldas and MachalillaLos diferentes individuos de las ballenas jorobadas pueden identificarse por los patrones de sus colas. Hasta ahora los científicos de Nazca han identificado más de 400 individuos diferentes en las áreas de reproducción de Esmeraldas y Machalilla
With our photo ID catalogues of the whale’s flukes, peduncle knobs and dorsal fins, we can follow their migration patterns along the Ecuadorian and South American coast. Besides the humpback whale research, the aim of the Marine Mammals Program is to study all other species and to improve the knowledge of marine mammal populations of continental Ecuador and the Galápagos.
In association with the Universidad San Francisco de Quito (USFQ), we train Ecuadorian and international students in marine mammal research in Esmeraldas during courses on the ecology of marine mammals held as a regular three credit course at USFQ.
Note:
Nazca Institute does not offer volunteer programs within the marine mammal projects.
