Manual corer to sample sediments in the seagrass meadows

Seagrass meadows, such as Posidonia oceanica, are characterised by intricate root systems that hold sediments, organic matter, pollutants and remains of other organisms, like spicules of sponges, scleritis of corals, shells of gastropods and bivalves, exoskeletons of crustaceans and echinoderms. Due to the vertical growth promoted by orthotropic rhizomes, these sediments represent archives of the past conditions and recent dynamics. Recently the accumulation of organic matter in seagrass meadow sediments was proved to play a relevant role in the global carbon storage [1], helping in keeping global changes under control. However, sampling is not easy due to the presence of strong roots that hinder the penetration of the sampler [2]. In order to overcome this issue, a light and portable hand corer was specifically designed and tested. It consists of an aluminium tube 1.20 m long with an external diameter of 6 cm (2 mm thick). One end has been provided with a Starrett® bi-metal dual pitch hole saw (diameter 56 mm), and a removable external plastic collar. The other end was fitted with a removable steel handle. Rubber plugs, one with a bleed valve, and a piston for sediment extrusion complete the equipment. The handle allows the operator to give a short and quick alternative rotation. This movement enables the hole saw to cut the roots, removing the major obstacle to the corer penetration. The collar permits the displacement of the external sediments facilitating the corer extraction, but it can be removed according to sediments features. The corer extraction must be done with the upper plug with the valve closed to avoid sediment loss. This valve permits the water purge during the insertion of the plugs. In different posidonia meadows, samples long up to 70 cm were obtained with a limited effort.

Poster presentation

Suggested references:

Producer: http://www.ilgavone.it/ Quotations and orders by email: info@ilgavone.com

Ponti M, Righetti A (2016) A manual corer to sample sediments in the seagrass meadows 2nd European Conference on Scientific Diving Book of abstracts, 9-11 May 2016, Lovén Centre Kristineberg, University of Gothenburg, Sweden, p 63 .

Custom frames for digital photo sampling

• For all underwater housings with circular porthole

• Built in stainless steel and high resistance plastic

• Anti-reflective matte black surface

• Lightweight, resistant and durable

• Installable and removable under water

• Standard sampling size 28 x 21 cm (4:3) = 0.0588 cm² ~ 1/17 m²

• Better performance with wide-angle cameras

• Custom sizes on request

Producer: http://www.ilgavone.it/ Quotations and orders by email: info@ilgavone.com

Suggested references and image analysis software:

Ponti M, Fava F, Abbiati M (2011) Spatial-temporal variability of epibenthic assemblages on subtidal biogenic reefs in the northern Adriatic Sea. Mar Biol 158:1447-1459 http://dx.doi.org/10.1007/s00227-011-1661-3

Ponti M, Fava F, Perlini RA, Giovanardi O, Abbiati M (2015) Benthic assemblages on artificial reefs in the northwestern Adriatic Sea: does structure type and age matter? Mar Environ Res 104:10-19 http://dx.doi.org/10.1016/j.marenvres.2014.12.004

Trygonis V, Sini M (2012) photoQuad: A dedicated seabed image processing software, and a comparative error analysis of four photoquadrat methods. J Exp Mar Biol Ecol 424-425:99-108 http://dx.doi.org/10.1016/j.jembe.2012.04.018. website

Sampling by scraping

Suggested references:

Bianchi CN, Pronzato R, Cattaneo-Vietti R, Benedetti-Cecchi L, Morri C, Pansini M, Chemello R, Milazzo M, Fraschetti S, Terlizzi A, Peirano A, Salvati E, Benzoni F, Calcinai B, Cerrano C, Bavestrello G (2004) Hard bottoms. In: Gambi MC, Dappiano M (eds) Mediterranean marine benthos: a manual of methods for its sampling and study, Vol 11. Società Italiana di Biologia Marina, Genova, p 185-216

Ponti M, Fava F, Perlini RA, Giovanardi O, Abbiati M (2015) Benthic assemblages on artificial reefs in the northwestern Adriatic Sea: does structure type and age matter? Mar Environ Res 104:10-19 http://dx.doi.org/10.1016/j.marenvres.2014.12.004

Percent cover visual estimation

Suggested references:

Bianchi CN, Pronzato R, Cattaneo-Vietti R, Benedetti-Cecchi L, Morri C, Pansini M, Chemello R, Milazzo M, Fraschetti S, Terlizzi A, Peirano A, Salvati E, Benzoni F, Calcinai B, Cerrano C, Bavestrello G (2004) Hard bottoms. In: Gambi MC, Dappiano M (eds) Mediterranean marine benthos: a manual of methods for its sampling and study, Vol 11. Società Italiana di Biologia Marina, Genova, p 185-216