How large is the world's largest fish? Measuring whale sharks Rhincodon typus with laser photogrammetry.

@article{Rohner2011HowLI,
  title={How large is the world's largest fish? Measuring whale sharks Rhincodon typus with laser photogrammetry.},
  author={Christoph A Rohner and Anthony J. Richardson and A D Marshall and Scarla J. Weeks and Simon J. Pierce},
  journal={Journal of fish biology},
  year={2011},
  volume={78 1},
  pages={
          378-85
        }
}
Laser photogrammetry was found to be a promising new cost-effective technique for measuring free-swimming whale sharks Rhincodon typus. Photogrammetric measurements were more precise than visual size estimates by experienced researchers, with results from the two methods differing by 9· 8 ± 1· 1% (mean ±s.e.). A new metric of total length and the length between the fifth gill and first dorsal fin (r² = 0· 93) is proposed to facilitate easy, accurate length measurements of whale sharks in the… 

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References

SHOWING 1-10 OF 38 REFERENCES

Population size and structure of whale sharks Rhincodon typus at Ningaloo Reef, Western Australia

We used photo-identification to produce estimates of population size and structure of whale sharks Rhincodon typus at Ningaloo Reef, Western Australia. We analysed photographs of whale sharks taken

A SIMPLE PHOTOGRAMMETRIC TECHNIQUE TO MEASURE SPERM WHALES AT SEA

For simple and fast size measurements at sea, a laser range finder was used alongside a digital camera to obtain distance to the fluke at the same time as photo-identification to suggest that the population in the Gulf of Mexico was made up of smaller animals than that of the gulf of California.

Laser photogrammetry to determine dorsal fin size in a population of bottlenose dolphins from Doubtful Sound, New Zealand

Laser photogrammetry was used to measure the dorsal fins of an entire resident population of bottlenose dolphins from Doubtful Sound, New Zealand, with males significantly larger than females in all measurements.

Analysis of whale shark Rhincondon typus aggregations near South Ari Atoll, Maldives Archipelago

These shark surveys along the southern fringe of the South Ari Atoll, Maldives Archi- pelago suggest that these sharks are either a small proportion of a local population or perhaps an even smaller component of a regional population in the western Indian Ocean.

SIZE‐CLASS SEGREGATION OF BOWHEAD WHALES DISCERNED THROUGH AERIAL STEREOPHOTOGRAMMETRY

Bowhead whales summering in the eastern Beaufort Sea in 1983 were measured through aerial stereophotogrammetry and significant segregation by bowhead whale length was found between four broad regions, confounds an accurate assessment of overall size-class composition of the population.

A simple laser photogrammetry technique for measuring Hector's dolphins (Cephalorhynchus hectori) in the field

The ability to measure and age individuals within a population has many important applications, for example, for examining growth and determining size class. We developed a simple photogrammetric

Population abundance and apparent survival of the Vulnerable whale shark Rhincodon typus in the Seychelles aggregation

These results are the first to suggest a highly transient population of whale sharks around the Seychelles, indicating that international or at least regional-scale conservation approaches are required.

LASER‐METRICS OF FREE‐RANGING KILLER WHALES

This work describes a simple approach for obtaining morphometric measurements based on photographing two laser dots that have been projected onto the body of a whale using two small laser-pointers, mounted in a parallel orientation to maintain a fixed and known separation distance.