Comparing Traditional and Modern Methods of Kākahi Translocation: Implications for Ecological Restoration

New Zealand Journal of Marine and Freshwater Research ISSN: 0028-8330 (Print) 1175-8805 (Online) Journal homepage: https://www.tandfonline.com/loi/tnzm20 Comparing traditional and modern methods of kākahi translocation: implications for ecological restoration Amber Julie McEwan, Aaria Ripeka Dobson-Waitere & Jeffrey S. Shima To cite this article: Amber Julie McEwan, Aaria Ripeka Dobson-Waitere & Jeffrey S. Shima (2019): Comparing traditional and modern methods of kākahi translocation: implications for ecological restoration, New Zealand Journal of Marine and Freshwater Research, DOI: 10.1080/00288330.2019.1636099 To link to this article: https://doi.org/10.1080/00288330.2019.1636099 Published online: 08 Jul 2019. Submit your article to this journal View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=tnzm20 NEW ZEALAND JOURNAL OF MARINE AND FRESHWATER RESEARCH https://doi.org/10.1080/00288330.2019.1636099 RESEARCH ARTICLE Comparing traditional and modern methods of kākahi translocation: implications for ecological restoration Amber Julie McEwana, Aaria Ripeka Dobson-Waitereb and Jeffrey S. Shimaa aSchool of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand; bZEALANDIA Te Māra a Tāne, Wellington, New Zealand ABSTRACT ARTICLE HISTORY Handling methods are an important determinant of translocation Received 31 January 2019 success. In Aotearoa/New Zealand, tangata whenua traditionally Accepted 21 June 2019 used insulated kete to translocate aquatic animals to new HANDLING EDITOR environments as part of ahumoana tawhito (ancient aquaculture). Joanne Clapcott In this study we investigated the influence of three transport methods (traditional [flax kete], modern [bucket], and a hybrid of KEYWORDS the two [bucket with flax support structures]) on the short-term Kākahi; freshwater mussel; performance (burrowing speed) of kākahi (freshwater mussels). translocation; burrowing; We also tested whether assisted release (planting kākahi in the Matauranga Māori substrate) resulted in enhanced burrowing speeds. Kākahi that were transported using the traditional method were slower to begin probing the substrate, but there was no difference in overall burrowing speed. We also found that assisted release resulted in faster burrowing speeds. We conclude that handling and release procedures can influence the short-term performance of translocated kākahi, and we recommend procedures for future translocation projects, including transporting animals in immersion vessels where practical, and planting them at the release site Introduction Translocations are increasingly used for the restoration of species and ecosystems (Fischer and Lindenmayer 2000; Seddon et al. 2014 and references therein). While translocation can be a valuable tool, negative outcomessuchasincreasedmortalityandlow reproductive rates can occur (Fischer and Lindenmayer 2000; Letty et al. 2007). The use of appropriate handling procedures is an important determinant of population estab- lishment (Dickens et al. 2010). Aquatic animals are particularly vulnerable to conditions in transport vessels, where excreta buildup and thermal stress can become an issue (Lim et al. 2003). Freshwater mussels (Bivalvia Palaeoheterodonta) are important components of many aquatic ecosystems, where they act as primary consumers (Spooner et al. 2012), and as ecosystem engineers–influencing water clarity by filter-feeding (Haag 2012) and biotur- bating sediments by burrowing (Vaughn and Hakenkamp 2001). Most species have a complex life history that includes a relatively sessile adult stage and a larval stage that is CONTACT Amber Julie McEwan [email protected] © 2019 The Royal Society of New Zealand 2 A. J. MCEWAN ET AL. parasitic on fishes, a strategy that facilitates dispersal and/or up-current migrations (Lydeard et al. 2004). Freshwater mussels are exposed to stressors throughout watersheds, including sedimentation, contamination, impoundment, river realignment (Williams et al. 2017; Naimo 1995; Brim Box and Mossa 1999), and changes to host fish populations (Watters 1996; Downing et al. 2010). Translocation has been identified as a key tool to combat freshwater mussel declines (Haag and Williams 2014). However, newly-translocated mussels are at heightened risk of displacement and predation until they have secured shelter by burrowing into the substrate (Peck et al. 2014). Aotearoa/New Zealand has three presently described species of freshwater mussel: Echyridella menziesii, E. aucklandica, and E. onekaka (Fenwick 2006; Marshall et al. 2014). The first two occur sympatrically in the Wellington region, where they are collec- tively referred to as kākahi by local mana whenua (indigenous Māori people with tribal authority in the region). Kākahi feature in many Aotearoa/New Zealand place-names, and their prevalence in whakataukī (Māori proverbs; Whaanga et al. 2018) is a strong indi- cator of the cultural importance of these animals. Kākahi are threatened by the suite of anthropogenic stressors that affect freshwater ecosystems throughout New Zealand (McDowall 2006; Allibone et al. 2010; McIntosh et al. 2010; Baskaran et al. 2009; Joy 2015; Larned et al. 2016), and the three species are classified by the New Zealand Department of Conservation as either ‘At Risk–Declining’ (E. menziesii), ‘Threatened–Nationally Vulnerable’ (E. aucklandica), or ‘Data Deficient’ (E. onekaka; Grainger et al. 2018 ). In 2018, the Zealandia wildlife sanctuary in Wellington proposed to introduce a translocated population of kākahi into a lake (called Roto Mahanga) within the sanctuary, for the purposes of conservation, education, and potential future bioremediation of the Kaiwharawhara catchment (McEwan 2018). The project is a long-term collaboration between multiple organisations, with knowledge-sharing as a specific goal. During planning discussions, transport and release methods were identified as an important factor in maximising both kākahi welfare during the translocation process, and short-term performance of kākahi at the release site. Predation of adult freshwater mussels tends to be opportunistic and in response to conditions that result in mussels being exposed (Cosgrove et al. 2007). In New Zealand, evidence of rat predation has been observed on freshwater mussel shells on the beach of a hydroelectricity reservoir (Moore et al. 2019), and wading birds have been seen feeding on kākahi in water that had been abruptly lowered as part of a farmland drainage scheme (A. McEwan Pers. Obs.). We recognised that the period immediately following translocation (i.e. before the animals have burrowed into the substrate) could be important as this is when they would be most vulnerable to predation or displacement. Experiments on freshwater mussels in India (Yusufzai et al. 2010) and the USA (Chen et al. 2001) showed that animals which were transported in wetted sacks were more stressed than those transported in immersion vessels (tissue glucose levels were used to measure stress). Chen et al. (2001) investigated 5 species, and found that the strength of stress responses varied between species. Kākahi have historically received little attention compared to other New Zealand fauna, and there is no published information available regarding appropriate translocation methods for these species. Tangata whenua have traditionally translocated aquatic animals to new environments as part of ahumoana tawhito (ancient aquaculture)–mainly to replenish traditional mahinga kai stocks and to create new food stores in other locations. Documented NEW ZEALAND JOURNAL OF MARINE AND FRESHWATER RESEARCH 3 examples of animal translocations include tuna (Anguilla spp. and kōura [Paranephrops planifrons] McDowall 2011), toheroa ([Paphies ventricosa] Futter 2011; Taikato and Ross 2018; Ross et al. in press), and kākahi (Rainforth 2008). Baskets woven from natural materials were common transport vessels for translocations. Examples of vessels include pōhā rimurapa (bull kelp baskets) and kete harakeke (flax baskets) packed with wet sphagnum moss. The benefits of incorporating such mātauranga Māori (Māori wisdom, but see Royal (2009) for a more detailed definition) in modern-day conservation management initiatives is becoming better understood in Aotearoa/New Zealand (e.g. Kusabs and Quin 2009; Awatere and Harmsworth 2014). However, it is important that intellectual property rights are respected by using appropriate procedures and obtaining appropriate permissions (Royal 2009). In this study we used laboratory mesocosm experiments to evaluate the influence of transport method: ‘traditional’ (kete stuffed with wet moss), ‘modern’ (lidded plastic bucket with water and an aerator), and ‘hybrid’ (bucket containing kete submerged in water and an aerator) on the short-term performance (burrowing speed) of kākahi. We also tested whether assisted release (planting kākahi in the substrate at the release site) resulted in enhanced burrowing speeds. Materials and methods Raranga (weaving) The kete used in the experiment were woven from pā harakeke (flax) and piritā (supple- jack) sourced from the same location as the kākahi. Materials were boiled and/or soaked prior to construction to leach out potentially harmful phytochemicals. The kete were designed using a combination of kete kono (food basket) and kete pipi (pipi basket) fea- tures, and the weaving process involved the use of karakia to acknowledge the whakapapa (genealogy) of the taonga (treasured

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