Sensors
Temperature:
In situ sensors for monitoring temperature variations have been used for a long time. However, in the Galapagos it may be possilbe to monitor sea surface temperatures by AVHRR (Advanced Very High Resolution Radiometer) satellite technology in conjunction with in situ sensors (Wellington, Strong, & Merlen 2001).
It was found that the satellite data came within .5 degrees Celsius (plus or minus) with the data from the in situ sensors for sea surface temperatures. However, this quality of data is limited to about a depth of 10m. Also, shallow waters very close to the shores of the islands in the archipelago are affected by heating, runoff, and tidal exchange, so the satellite data would not be totally accurate (Wellington, Strong, & Merlen 2001).
However, using the satellite data in places where it is reliable would help lower the amount of sensors in the environment. In situ sensors would only need to be placed in areas very close to shores and at depths greater than 10m.
Tags:
In the Galapagos, two types of tags have been used on sharks to monitor their movements. These are tethered tags and archival pop-up tags. The tethered tags provide real-time data but hinder the animal's movements and often fall off. The pop-up tags have had more success. They transmit archived data to the Argos Satellite System.
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