Caulerpa cylindracea (Sonder)

Davidson, Alisha D., Campbell, Marnie L., Hewitt, Chad L. & Schaffelke, Britta, 2015, Assessing the impacts of nonindigenous marine macroalgae: an update of current knowledge, Botanica Marina (Warsaw, Poland) 58 (2), pp. 55-79 : 61-62

Caulerpa cylindracea

Caulerpa cylindracea has been spreading in the Mediterranean Sea since the early 1990s ( Verlaque et al. 2003, 2004, Klein and Verlaque 2008). In Italy, overgrowth by C. cylindracea reduced diversity and abundance of native macroalgae, especially turf and encrusting species ( Piazzi et al. 2001a). In mixed sea grass meadows of Cymodocea nodosa (Ucria) Ascherson and Zostera noltii Hornemann , C. cylindracea decreased shoot density of C. nodosa but increased density of Z. noltii ( Ceccherelli and Campo 2002) .

Where they co-occur, C. cylindracea is competitively superior to C. taxifolia , and growth rates of the former species are higher ( Piazzi et al. 2001b, Piazzi and Ceccherelli 2002). The establishment of C. cylindracea most commonly led to the reduced abundance and species number of native algal growth forms: canopy-forming ( Bulleri et al. 2010), as well as encrusting, foliose and articulated forms ( Piazzi and Balata 2008, 2009). The decline in the latter three was attributed to increased sedimentation ( Piazzi et al. 2007a). Caulerpa cylindracea was observed to reduce survival and biomass of live coral colonies ( KruŽić et al. 2008, Žuljević et al. 2011, Cebrian et al. 2012).

Several studies also demonstrated an impact on macroinvertebrates, such as lower amphipod richness and abundance, different species composition, and changes in food web structure compared with sea grass beds ( Vázquez-Luis et al. 2008, 2009, Deudero et al. 2011, Lorenti et al. 2011, Pacciardi et al. 2011, Vázquiz-Luis 2013, Deudero et al. 2014). Finally, C. cylindracea was implicated in reducing the physical condition of white seabream ( Diplodus sargus Linnaeus ), via the bioaccumulation of the pest metabolite caulerpyne ( Terlizzi et al. 2011).

The one potential human health effect found in the review was related to the potentially toxic effects of C. cylindracea on white seabream, which causes a change in the fatty acid composition of this fish (which is eaten by humans), making it an improved source of essential fatty acids for human nutrition ( Felline et al. 2014). However, all impact studies were limited to the Mediterranean. Effects on diversity, total cover, and articulated algae persisted even after C. cylindracea had been removed. For example, Klein and Verlaque (2011) found lower values for these characteristics 18 months after C. cylindracea was removed. Although the invasion history of this species is relatively short, the research (e.g., Klein and Verlaque 2011) suggests that the current temporal reversibility of these impacts is likely to be moderate to high (recovery extending into decades or longer; Hewitt et al. 2011a, Ojaveer et al. 2015).