Contact Us

Archive | Marine Species Ecology

Bivalve Spondylus

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

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 calciferS. 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.

Galería de fotos

More Information:
Alfred Wegener Institute for Polar and Marine Research

Comments (0)

Marine mammals

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.

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.

Comments (0)

Advertise Here

Photos from our Flickr stream

See all photos

Advertise Here

Social Networks