Palmerston Island Natural Resource Management Plan 2020

Photo: Cooks Islet, Palmerston Island (Alanna Smith, 2018)

Author: Te Ipukarea Society Inc. (Kelvin Passfield, Alanna Smith and Kate Mackessar)

PO Box 649,

Funded with the support of:

The Ridge to Reef Project through the National Environment Service funded by the Global Environmental Facility (GEF) and facilitated by the United Nations Development Programme (UNDP)

Acknowledgments

Meitaki ma’ata to the following people and organisations:

The Cook Islands Ridge to Reef Project for funding the Palmerston Natural Resource Management Plan.

Palmerston Executive Officer, Arthur Neale for assisting the report team with the necessary information needed and commenting on the draft.

All the government departments involved in providing additional information and reports required to help develop this Management Plan, in particular the National Environment Service, Ministry of Marine Resources and Ministry of Agriculture.

Ian Bertram at the Secretariat for the Pacific Community (SPC) for supplying additional reference material.

Hayley Weeks, Manager of the R2R Project, Kirby Morejohn and Lara Ainsley from the Ministry of Marine Resources, for the constructive edits and feedback, as well as use of some photographs.

National Heritage Trust Jo Brider and Gerald McCormack for verification of some species.

Graham McDonald for some of the images used.

Executive Summary

As a result of Palmerston’s isolated position in the southern Cook Islands, many of its natural resources, predominantly marine resources, are heavily relied upon by local residents for subsistence. Though resources are mostly able to support subsistence demand, there are growing concerns around commercial exports. Commercial exploitation has been influenced by income opportunities, more efficient catch methods, and improvements in technology such as 24-hour power for freezers. Some of these have proven unsustainable.

The status of numerous natural resources listed within this Management Plan are of concern and require management. This is particularly true for the parrotfish, which continues to be identified as most at risk of over-exploitation due to its commercial harvest to meet the demand in Rarotonga.

Tridacnid clams (pa’ua) stocks are also of concern. Surveys in 2018 found pa’ua numbers represented less than one percent of all invertebrates recorded. Of further national concern, records from 2008-19 showed that nearly 40 tons of pa’ua meat was exported from the Cook Islands within a 12-year period. The origin within the Cook Islands was not specified.

Turtles were once commonly harvested on Palmerston for their shells and meat, with shells sold to passing yachts. Nesting turtles found on Palmerston include the IUCN Red Listed green turtle (Chelonia mydas) and hawksbill turtle (Eretmochelys imbricata). Though there are no formalised regulations in place to protect these turtles, there are community rules to protect female turtles. However, the sale of turtle meat to Rarotonga is apparently ongoing but not officially reported.

The commercial market for crabs (Birgus latro) is also of growing concern, with requests from Rarotonga on the rise. As a result, catch rates have increased. More recently tupa crabs (Cardisoma carnifex) have also been exported from Palmerston for the Rarotongan market, raising concerns for the sustainability of this species as well.

Anecdotal information suggests there has been a drop in annual harvested numbers of red tailed tropic birds (Phaethon rubricauda, Bosun bird). Though a traditional quota of 2 birds per person per month is in place from June to August, harvesting outside these months is believed to be occurring.

Species specific management recommendations are made within the following document. There was emphasis from the current standing Executive Officer (EO) Arthur Neale that educational resources and tools need to be developed to promote sustainable mindsets amongst the local community.

The following management plan has been developed as a living document that aims to help guide the island’s sustainable development. It is recommended that the document is revisited regularly, at least every 5 years, and modified as required.

Contents

1. BACKGROUND ...... 5 1.1 Geography and Geology ...... 5 1.2 Regional Setting: Location and access ...... 6 1.3 Colonial History and Governance ...... 7 1.4 Socioeconomics in Palmerston ...... 8 1.5 Natural Resources Research history ...... 8 2. PURPOSE AND SCOPE OF PLAN ...... 9 3. NATURAL RESOURCES MANAGEMENT ...... 10 3.1 Parrotfish ...... 11 3.1.1 Parrotfish Management Recommendations ...... 12 3.2 Other finfish ...... 14 3.2.1 Other Finfish Management Recommendations ...... 16 3.3 Turtles ...... 16 3.3.1 Turtle Management Recommendations ...... 18 3.4 Crabs ...... 19 3.4.1 Crab Management Recommendations ...... 20 3.5 Pa’ua (Giant Clams) ...... 21 3.5.1 Pa’ua Management Recommendations ...... 22 3.6 Tropical spiny lobsters ...... 23 3.6.1 Tropical spiny lobsters management recommendations ...... 23 3.7 Trochus ...... 23 3.7.1 Trochus Management Recommendations ...... 24 3.8 Sea Cucumbers ...... 24 3.8.1 Sea cucumber management recommendations ...... 26 3.9 Birds ...... 26 3.9.1 Bird Management Recommendations ...... 29 3.10 Trees ...... 30 3.10.1 Tree management recommendations ...... 30 3.11 Other species ...... 30 4. ADDITIONAL MANAGEMENT ISSUES ...... 31 4.1 Visiting yachts and cruise ...... 31 4.1.1 Management recommendations ...... 31 4.2 Rat Eradication and biosecurity...... 31 4.3 Biosecurity ...... 32 5. CONCLUSION ...... 32 6. REFERENCES ...... 34 7. APPENDICES ...... 37

1. BACKGROUND

1.1 Geography and Geology

Palmerston is located at 1802.975’S and 16309.372’W. It is approximately 500km north of Rarotonga and 367km North West of and is one of seven atolls in the Cook Islands. Apart from , it is the furthest south of the atolls and is usually included in the grouping of nine islands commonly known as the Southern Group. The remaining five atolls and one sand cay make up the northern Cook Islands.

Similar to the other atolls, Palmerston consists of coral reefs located around a on the top of a submerged volcano, rising from a depth of 4000m. Palmerston atoll consists of six islets (motu); Home, North, Toms, Primrose, Cooks and Birds Island, joined together in a rough diamond shape by a reef forming a 30km barrier around an enclosed lagoon. Home Island, also known as Palmerston Island, is the largest motu and has the highest elevation above sea level of around 5 meters (OPM/PIC undated). This is the motu on which the people of Palmerston live. There was a total of 58 residents at the last census in 2016 (Cook Islands Statistics Office 2018). The total land area of all six motu combined is approximately 183.2 ha (Smith 2018).

The atoll is 12 km long and 9.5 km wide, with over one-half of the lagoon deeper than 20 m, and a maximum depth reaching 35 m (Pinca et al. 2009). The lagoon contains many remote coral banks and coral heads. The motu are small and scattered widely along the reef. It is likely that Palmerston’s motu had greater land area in the past, but over time, this has been weathered down by hurricane seas (Wood 1967).

Each of the motu are separated by a reef flat. In total the covers about 15 km2 while the entire atoll covers approximately 56 km2 (Google Earth 2020). The distance between each of the motu varies from 900m to 7 km, with a total lagoon area of approximately 35 km2 (National Environment Service 2011).

Palmerston is particularly susceptible to the impacts of storms and cyclones, due to its location and elevation, rising only a few meters above sea level. Studies have shown that Palmerston is the most likely island to be visited by cyclones of all the islands in the Cook Islands group, with an average of 0.7 cyclones per year from 1970 to 2006 (de Scally 2008).

Additional impacts from climate change such as coral bleaching and resultant biodiversity loss are expected. Agriculture is similarly vulnerable to seasonal changes in climate as well as extreme weather events. Climate change also presents new challenges regarding the distribution and management of the limited agriculture in Palmerston. Changes in climate are also anticipated to affect the distribution of pathogens, such as the dengue fever virus, which poses increased risks to public health (JNAPII, 2016-2020). 1.2 Regional Setting: Location and access

Palmerston has no airstrip and therefore relies on inter-island shipping for transportation and food supply. It takes almost 2 days to travel the 500km from the main island of Rarotonga. The frequency of cargo boats visiting Palmerston usually varies between 2 and 4 months and can sometimes be much longer due to breakdowns and bad weather.

Figure 1: Map of Palmerston Atoll, naming individual islets (motu) and sand cays Small cruise ships and yachts also visit the island, creating additional revenue for locals. Local handcrafts and souvenirs are sold to these visitors. In 2016, a total of 64 yachts visited the island of Palmerston (OPM/PIC undated). Several small passages on the leeward side make it possible for small boats to enter the lagoon, but there is no safe entry for larger boats. Eight moorings are made available for yachts on the NW of the island. An anchorage with a coral bottom depth of 10 to 15m is located on the west side of the atoll, extending away from the fringing reef. Visiting months for yachts are between May and September, i.e., outside cyclone season. Small cruise ships are also known to visit Palmerston but much less frequently, typically one or two annually.

1.3 Colonial History and Governance

On Captain Cook’s second voyage around the world in 1774 he was possibly the first European to visit Palmerston Island. He named it in honor of Lord Palmerston, who was the First Lord of the British Admiralty (Synge 1903). It is highly likely however that the early Polynesian voyagers would have discovered Palmerston well before Cook’s first visit.

In 1777, Palmerston Island was again visited by Captain Cook and a number of other vessels. The Aorai, under the command of Captain Hart, visited in 1863. The vessel owner and copra agent John Branden had hired William Richard Marsters to be his agent on Palmerston (Pryor 1980, Edwards 1915, Maude & Crocombe 1962). Marsters was accompanied by 4 wives, 3 of whom provided him with children.

By 1888, Marsters had claimed complete ownership of Palmerston, and with three of his wives then went on to populate the island with three branches of the family (Crocombe, 1964). Their descendants still live on the island today. The three branches each have their own section of land on the main island for houses and crops, as well as sections of the other islets (Pryor 1980).

In 1954, the Marsters family were granted full ownership of Palmerston due to amendments made to the Cook Islands Act 1915, passed by the Parliament (Pryor 1980). The Act also designated 10 acres of land for crown purposes. Though the Act mentions sites such as the radio station, water supply tanks and the school building, these areas have not been clearly defined (Pryor 1980).

Today, Palmerston has its own island government, established under the Island Government Act 2012-13. It consists of the Mayor, elected from any of the individual heads of the three families, three other representatives of the three families, and the Member of Parliament, who resides in Rarotonga. Members of the Council are elected according to the island customs. The Member of Parliament for Palmerston is shared with a constituency in Rarotonga, and represents Ruatonga, Avatiu and Palmerston (RAPA). An Executive Officer is also appointed by the Island Government, after approval by the Public Service Commissioner, and is the senior public servant on the island.

Under the Island Government Act 2012-13, the Island Council can make by-laws for the licensing and regulation of any activities or matters affecting the island. Despite this provision, there are currently no by-laws in place around the management of Palmerston’s natural resources (pers comm A. Neale 2020). 1.4 Socioeconomics in Palmerston

Palmerston’s geographically isolated location in the Cook Islands and lack of an air strip means that local residents are limited in availability of imported goods to those they receive on the irregular shipping service from Rarotonga, or sometimes barter for from visiting yachts. The Palmerston community are therefore heavily dependent on their surrounding reef and lagoon resources for their subsistence and livelihood. With a population of less than 60, demand on natural resources for subsistence is unlikely to exceed local supply. However, there are major concerns associated with commercial and non-commercial export of some of these resources to Rarotonga and beyond.

The onset of modern development in the past 40 years has brought changes in health, education, income and lifestyle. For example, as of 2015 Palmerston became 100% solar powered, allowing for constant power supply compared to the previous diesel-powered supply of only 12 hours per day (CI News, 2015). This has resulted in the purchase of multiple freezers to better store harvested marine resources, predominantly for commercial trade. Catch methods have also modernised having shifted from paddle canoes to motorised boats. Hook and line fishing methods have largely been replaced with gillnets for inshore fisheries.

1.5 Natural Resources Research History

There have been several research expeditions over the past 30 years centered around Palmerston and its inhabitants. These projects have highlighted the benefit in having a management plan to guide Palmerston residents on the sustainable use of their resources and are discussed in more detail later in this plan.

In 1959, Ron Crocombe collected information on land tenure in Palmerston as a part of his PhD research. He also touched on some aspects of natural resource conservation, in relation to the traditional way in which resources are utilised, sold and shared. This information was later updated by Rev. William Marsters and included as a chapter in a book on land tenure in the atolls edited by Crocombe. (Crocombe & Marsters,1987).

In 1988 a group of scientists visited the island of Palmerston to conduct a marine resource survey. These included scientists from the Ministry of Marine Resources (MMR), the South Pacific Commission (now the Secretariat for the Pacific Community, SPC), the Forum Fisheries Agency (FFA), and several other Pacific islands national fisheries agencies (Tuvalu, Fiji, and Kiribati). This was initiated mainly because of a concern for the parrotfish stock, which was heavily exploited and subject to an export ban at the time of the visit (Preston et al. 1995). Several management recommendations were made in that report, and these are discussed later.

A follow up survey was conducted in 2007 with support from SPC, in which some of the results of the 1988 report were revisited, particularly in regard to the parrotfish (Pinca et al. 2009). Despite this, parrotfish stocks remain a major concern for the Palmerston Island Council of today (pers comm, A. Neale 2020). More details on the contents of these two research reports are provided later in this document and have helped inform some of the recommendations made. In 2013, the Khaled bin Sultan Living Oceans Foundation (KSLOF) conducted a coral reef survey and mapping expedition in Rarotonga, Aitutaki and Palmerston. The expedition was designed to assess the impact of anthropogenic and natural disturbances on each of the islands’ reef ecosystems, such as runoff, climate change, storm damage and Crown of Thorns outbreaks (Purkis et al. 2018). The survey provided a snapshot of the status of a number of the resources in Palmerston but did not make any management recommendations. More details on specific species are provided later in this Plan.

The most recent natural resource survey was conducted in October 2018 under the Ridge to Reef (R2R) Project. This was undertaken by the in-shore team from the Ministry of Marine Resources (MMR), Ministry of Agriculture (MoA), National Environment Service (NES) and the Marae Moana Coordination Office, utilising Te Ipukarea Society (TIS) staff. Research conducted included a nearshore marine resource, coconut palm, and seabird surveys. This expedition was an information gathering exercise to assist in the development of this plan. References for these surveys can be found in the reference section.

2. PURPOSE AND SCOPE OF PLAN

Natural resources are extremely important to the survival of the inhabitants residing on the remote Palmerston Island. According to a 2007 study, they have among the highest consumption per capita in the world, at 111kg per person per year (Pinca et al. 2009). Consequently, that study recommends that the island develop effective by-laws relating to ecosystems and biodiversity management, and adoption of best practices for managing the reefs and as key habitats of these resources. This includes developing a reef fish resources management plan, regulating the harvesting of other sea and lagoon resources based on good practice and sustainable principles, and managing the harvest of terrestrial resources such as coconut crabs, seabirds and birds’ eggs in a sustainable manner (OPM/PIC undated).

This Palmerston Island National Resource Management Plan (the Plan) has been prepared with funding through the Cook Islands R2R project, led by National Environment Service (NES). It is supported by the United Nations Development Programme (UNDP) and is funded by Global Environment Facility (GEF). The Plan was developed at the request of the Palmerston Island Council and is intended to support the people of Palmerston in managing their natural resources in a sustainable manner, as well as government agencies and other key stakeholders that play a supportive role in the conservation of natural resources in Palmerston. This will facilitate maintenance of their livelihoods while at the same time avoid negatively impacting their home and the natural resources on which these livelihoods depend.

As noted in Pinca et al. (2009), the objective of developing and implementing an effective management plan can only be reached with full cooperation between the island’s community and Government support agencies, with a strong focus on ownership by the Palmerston community. This community has requested that this Plan be developed as a living document so that it can be adapted as required in future. It includes educational activities that support sustainable behavioral changes. Information provided in the Palmerston Island Community Strategic Plan 2017 – 2020, (OPM/PIC, undated), which was prepared with input from the community, was also used to inform the Plan. This Plan incorporates many of the recommendations in the forementioned reports. It covers the main species utilised by the people, as well as several key species that are at risk due to climate change or other external factors.

3. NATURAL RESOURCES MANAGEMENT

Palmerston could be considered fortunate in a number of ways. Because of its isolation and small population, there is not a great deal of pressure on resources to meet local subsistence demand. The main impacts on the resources of the island come from the industriousness of the people themselves, and increasingly from climate change impacts.

The coral reef surveys conducted by the Khaled bin Sultan Living Oceans Foundation (KSLOF) in 2013 found that Palmerston had overall the healthiest reef system of the three islands visited within the Cook Islands (Rarotonga, Aitutaki and Palmerston). Healthy reef systems were found to be understandably influenced by human population numbers, where the greater the population the more degraded the coral reef ecosystem was. Surveys found that Palmerston had live coral coverage that ranged on average from 50-62%, which was some of the highest coral cover recorded by KSLOF in the South Pacific (Purkis et al. 2018). It must be remembered however that this was a snapshot survey, and not particularly comprehensive.

The Ministry of Marine Resources did more extensive coral cover surveys in 2018. They reported live coral cover to average 23% (Ainley and Morejohn, 2019). This is significantly lower than the 50-62% reported by KSLOF and would certainly not indicate that coral cover was relatively high or that the reefs were in a healthy state. In comparison to other Cook Islands, Palmerston’s coral cover is about average and typical for the Southern Group and lower than where MMR surveyed in the Northern Group (L. Ainley, pers,comm.).

The KSLOF expedition also identified that Palmerston had a higher mean species richness and biomass, with significantly more large predatory fish than Aitutaki or Rarotonga. Palmerston also had the highest mean species richness (Purkis et al., 2018). This may also be a result of human pressure on fish diversity at the other two surveyed islands, or just the natural distribution of biodiversity in such a scattered archipelago.

There has been concern for over 30 years that Palmerston has been overharvesting their parrotfish stocks (Preston et al. 1995; Pinca et al. 2009, Ainley and Morejohn, 2019). Giant clam (Tridacna maxima, pa’ua) numbers are also reported to be lower than most other islands in the Cook Islands (Pinca et al. 2009, Ainley and Morejohn 2019). While most species are not currently harvested in commercial quantities on Palmerston, demand from Rarotonga is having an impact on some species, which are also covered below.

Based on the above information as well as knowledge from the Palmerston community, the key priority species identified as needing management both now and potentially in the near future are discussed below. Management options are provided for the consideration of the Island Council and other key supporting stakeholders to decide on the best options for the wellbeing of the people of Palmerston and the biodiversity, habitats and ecosystems on which they rely.

3.1 Parrotfish

The parrotfish family of (Scaridae) is the key commercially exploited resource in Palmerston. The fish are caught by gillnets on the reef flats and inside the lagoon.

Figure 2: Pacific Longnose Parrotfish (Hipposcarus longiceps) (Photo: Kirby Morejohn/ MMR)

There is a concern that if fish are being caught before they reach sexual maturity they will not have had the chance to reproduce. As a result of past concerns over the catching of small fish, and with advice from the Ministry of Marine Resources, fishermen have been acquiring larger 5 inch mesh nets.

However, anecdotal reports indicate that a number of fishermen persist in using the 3 inch mesh, and are therefore catching smaller fish (pers comm, B. Masters). For example, the Pacific Longnose Parrotfish (Hipposcarus longiceps, rei), the most commonly exploited species, are now often caught at 15 to 17cm fork length (FL), with the fillets of around 10 fish required to make 1kg (pers comm, B. Masters). In 1988, the average size from catch sampling was around 36 cm (inferred from graph, figure 4.1 in Preston et al., 2005). In 2007, the average size was 30cm (Pinca et al., 2009). The MMR survey undertaken in 2018 did not report length data and had more of an emphasis on density. The average parrotfish density was 5 ind/100m2 recorded in the fore reef. If the 2020 estimate of 15 to 17 cm is accurate, this shows a significant and continuing drop in the average size. There is a need to collect more length frequency data in order to determine the trend in reduction in average size over the past several decades.

The apparent decrease in size is particularly concerning because this species, like all parrotfish, is a diandric protogynous hermaphrodite. This means they start their life as females, and later in life a percentage change into males. H. longiceps reaches sexual maturity as a female at around 33 cm FL, and most individuals transform into a male at around 40cm (Taylor and Cruz, 2017). If the fish are being caught at around 20cm, they will not have reached sexual maturity and therefore will not be reproducing, further impacting total numbers and overall sustainability.

Fig 3. A school of Chlorurus microrhinos parrotfish in Palmerston lagoon (Photo Graham McDonald)

3.1.1 Parrotfish Management Recommendations

There have been a number of management recommendations made over the years for the Palmerston parrotfish fishery, going back at least to 1988 (Preston et al. 1995). However, very few have been initiated, or only implemented for a short time. Nevertheless, these recommendations are repeated here, along with several others.

There is currently a two year ra’ui on netting parrotfish for approximately 50% of the island, from the western side of Cooks Islet to the eastern side of Kitsap banks, starting from January 2020 (pers comm A. Neale 2020) (figure 4). Based on the 2018 MMR survey, parrotfish densities are relatively low in the newly established ra’ui area (Ainley and Morejohn 2019). It may be better to locate the ra’ui in a location with higher densities of parrotfish, so that a spillover effect into less populated parts of the reef can occur. The ra’ui is unlikely to be sufficient to restore parrotfish stocks on its own. It is therefore recommended that additional management methods be applied.

Figure 4. Showing the approximate extent of the current parrotfish ra’ui.

Suggested management options include:

1. Establish minimum size limits. Research has suggested that catching the larger fish, after they have changed sex to males, may be a useful management objective (Pavlowich et al, 2018). 2. Place a limit (quota) on the total catch, per fisherman or per family, of parrotfish caught, or being sent, to Rarotonga. This would require monitoring of exports by the authorities. 3. Total ban on parrotfish netting until the average size returns to at least that recorded in 2009. However, this would have serious implications on livelihoods, and would only be possible if there were alternative sources of income. It may require a move to another fishery resource or possibly increased tourism opportunities. Anchored fish aggregation devices (FADs) have been deployed over the years, and as recently as 2018, as one way to shift fishing pressure to offshore species. 4. Nets smaller than 5 inch mesh should be banned for the parrotfish fishery. It may be best if these smaller mesh size nets were banned for all fisheries, as it would be difficult to police if they were allowed for other species, which could be achieved through by- laws. A buyback scheme could be initiated as a way to remove nets from the lagoon fishery. The already established monitoring programme should be closely followed to assess the impacts of the changes in nets on the catch, as well as on the livelihoods of fishers. 5. Perhaps the best option for management would be to initiate a ban on spawning aggregations or known spawning locations. This may require a number of short closures as some species spawn several times each year and would involve some initial research into spawning seasons and locations for parrotfish, though fishing communities usually have some local knowledge of the timing and location of spawning aggregations. 6. The resident fisheries officer employed by MMR should continue to collect regular parrotfish size frequency data to inform future management decisions to open or close the fishery. 7. Some basic parrot fish biology should be taught in the local school, based on the SPC Procfish Parrotfish fact sheet1 (Appendix 1).

3.2 Other finfish

Apart from parrotfish, Palmerston has a variety of other finfish species, none of which are targeted for export to the same extent as parrotfish. Preston et al. (1995) listed all finfish known from Palmerston in an appendix to the 1995 report. A copy of this list is attached as Appendix 2. Note that some species names may have been revised since 1988.

In 2007, total finfish catch was estimated at 31.2 tonne) per year (mt/year), based on an extrapolation of household surveys (Pinca et al. 2009). This compares to Palmerston’s actual subsistence demand of only 7.8 t/year (Pinca et al. 2009). These results demonstrate that about 25% of all catches were for subsistence needs whilst the remaining 75% (23.4 t/year) were either exported for commercial or non-commercial purposes. Most of the fish were taken from the lagoon reef (93%) and (7%) from the outer reef (Pinca et al. 2009).

Of those finfish found in Palmerston, the Humphead Wrasse (Cheilinus undulatus, Maratea) is listed as endangered on the IUCN Redlist (Russell, 2004). It is the largest member of the wrasse family and like parrotfish undergoes sex reversal from female to male. The majority of animals in the population develop first as females, reaching sexual maturity at an age of approximately five years (approximately 35-50cm). At approximately nine years (~70cm) they start to develop as males. They are susceptible to over-exploitation due to a life history that involves late sexual maturation and long life of over 30 years (AFMA, undated). Catch rates for this species on Palmerston are unknown, but this species has a reputation of being ciguatoxic, which has likely had indirect conservation benefit for the species (Preston et al. 1995).

Rabbitfish (Siganus argenteus, Morava) are harvested from November to March each year during spawning aggregations, (Preston et al. 1995). Schools of rabbitfish are known to gather between Palmerston and Toms Islet between November and February, presumably to spawn. Gillnets with a mesh size of 3 inches are typically used during each fishing event which can take up to about eight hours (Pinca et al. 2009). Total annual catches during 2007 were estimated about 750-800 kg (average size 32 cm FL). The fish are usually eaten on the island or shared with families elsewhere (Pinca et al. 2009). These are therefore understood to be currently harvested at sustainable levels due to limited harvest period and lack of export. This status should be monitored, for example by collection of length-frequency data, to ensure spawning aggregations are not being negatively affected and the use of net mesh size is not inadvertently impacting other species, as discussed in the previous section.

1 https://www.spc.int/DigitalLibrary/Doc/FAME/Brochures/Anon_11_ISFC_04_Parrotfish.pdf .

Fig. 5. Rabbitfish (Siganus argenteus) in Palmerston Lagoon (Photo Graham McDonald)

Mullet (Crenimugil crenilabis, Kanae) and other mullet species are seasonally caught by gillnets, fishing on the reef flat for several nights either side of the full moon (Preston et al. 1995). The seasonality of this fishery may be linked to spawning cycles. Apart from the 1988 marine resource survey by Preston et al. (1995), there is no later information on catches that would be useful to inform management recommendations.

Fig. 6. A school of mullet (Crenimugi crenilabus) in Palmerston lagoon (Photo Graham McDonald)

Household surveys in 2007 recorded that there was an overall community perception of a historical decline in reef and lagoon finfish resources. (Pinca et al. 2009). There was a general perception that abundance and size of finfish had reduced over a 10-year period, though there is no data available to support this. This perceived drop in abundance and size could be explained by changes in fishing strategies and technology that started in the 1980s and early 1990s. These included the use of gillnets, outboard engines to replace paddle canoes, freezers, and increased export trade due to increased frequency of boat trips to and from Rarotonga, plus a growing demand for the tourism restaurant trade.

3.2.1 Other Finfish Management Recommendations

1. Due to their endangered status, there should be no export of maratea from Palmerston. Those under 40cm fork length should not be taken, as they are unlikely to have reached sexual maturity. Also large maratea over 70cm of size should be protected in order to maintain a sufficient number of males in the population. Therefore, a size limit of 40-70cm is recommended. 2. In order to obtain a more concise understanding of finfish population numbers and potential species that may require further management, it is recommended that fishers’ log sheets are simplified for fishers, making them easier to complete. Alternatively, they should be encouraged to provide information to the fisheries office for input into the TAILS app. 3. Catch numbers and sizes should also be sampled and recorded, as this can be used to confirm any perceptions of reductions in size and number of fish. This is particularly for the more commonly netted species of rabbitfish and mullet. More information on catches is needed to inform any future management decisions for these species.

3.3 Turtles

Palmerston has been known for several decades as one of the most important sea turtle nesting sites in the Cook Islands (Balazs 1995, Pritchard 1995), alongside Tongareva Atoll (White 2012).

Sea turtles nest in Palmerston between the months of November to March (White 2012). This includes the Green turtle (Chelonia mydas, onu kai) listed as endangered in the IUCN RedList (Seminoff 2004). Additionally, the Hawksbill turtle (Eretmochelys imbricata, onu taratara), listed as Critically Endangered in the IUCN RedList (Mortimer & Donnelly 2008), has also been observed nesting in Palmerston but in much lower numbers than the Green. The first recorded Hawksbill nesting observation was made in 2012 (White 2012).

The Loggerhead (Caretta caretta, onu) South Pacific sub population is listed as Critically Endangered in the IUCN RedList (Limpus & Casale 2015). It has been reportedly sighted from Palmerston Atoll, although it is not known to be found nesting there (pers comm B. Masters 2010 in White 2012). It is listed as occurring in Palmerston in the Cook Islands Biodiversity Database and identified from a video by Hoyt Peckham in the year 2000 (McCormack 2009- 2017). However, a survey of Palmerston in 2012 did not locate any of this species. It is reported to be extremely rare in the Cook Islands and is listed on the IUCN RedList as vulnerable globally (Casale and Tucker, 2017).

Fig. 7.: A green turtle resting on a coral head in Palmerston lagoon (Photo: Kirby Morejohn/ MMR)

Both live turtles and eggs, the vast majority being green turtle, were harvested in the past on Palmerston Island (Preston et al. 1995). According to Crocombe and Marsters, during the 1950s and before, swimming turtles could be taken by any person in Palmerston at any time. However the turtle meat was considered to belong to everyone, and shared equally among the community. The catcher retained ownership of the shell and usually sold it, for ten to twenty shillings at that time, to someone on the trading schooner or by taking it to Rarotonga. If a live turtle was sold to a passing , the catcher could keep all the proceeds for himself (Crocombe and Marsters, 1987).

During nesting times, turtles were captured at night and the eggs were collected (Preston 1995). Turtles were harvested for subsistence use or to send to family and friends in Rarotonga (Preston et al. 1995). Sometimes the turtles were sent live. Shells around 50 cm were also harvested for sale generating approximately NZD$50 each (Preston et al. 1995).

Under mutual community agreements, the spearing of turtles has been banned since 1995 and commercial harvest was discouraged (Preston 1995). Since this ban, there has been no evidence of further spearing, suggesting it is no longer practiced (pers comm A. Neale 2020). Though commercial harvest of turtles has been discouraged, it is still practiced today by several households (pers comm A. Neale 2020). The harvesting of turtles on Palmerston for export to Rarotonga persists to this day, due in part to the demand for turtle meat from Rarotonga (pers comm A. Neale 2020).

Key turtle sites on the island include Cook’s and Tom’s Isles in the south, which are frequently visited by nesting turtles (White 2012, Ainley and Morejohn 2019). A total of 24 nests were observed on Cooks Islets in 2018, 4 times more than found on any other motu. Turtles have been known to nest on Primrose Islet and occasionally on Bird and North Islets. Green turtles predominantly nest seasonally on these islets over the summer from November to March (White 2012).

Fig. 8. Cutting up turtle meat for distribution to the Palmerston community, 1988 (Photo: Kelvin Passfield)

The Cook Islands Government has committed to protecting turtles and their habitats under the Convention of Migratory Species (CMS), in which both Green and Hawksbill turtles are listed in Appendices I and II2. The Ministry of Marine Resources has raised awareness about removing hooks from turtles and minimising bycatch in the longline fishery. However, apart from turtle conservation measures applying to the industrial offshore fishery, under the West and Central Pacific Fisheries Commission (WCPFC) there are currently no regulations in place for turtle protection in the Cook Islands.

3.3.1 Turtle Management Recommendations

Over the past decade, some of the inhabitants of Palmerston have adopted a more conservative approach to the harvest of turtles and their eggs. However, turtle harvesting still continues, with reports of frozen turtle meat being sent to Rarotonga.

It is recommended that loggerhead and hawksbill turtles should be completely protected due to their regional and global threatened status. The green turtle is the only species that could maintain a very limited harvest for subsistence. No turtles should be taken while laying eggs or while mating. Nests should not be disturbed.

It is further recommended that the export of turtles and turtle meat from Palmerston be banned; turtle meat should only be consumed on Palmerston, and records should be kept.

To improve data availability around these species of turtles present and nesting in Palmerston, annual community-based monitoring surveys are recommended. Not only would annual

2 https://www.cms.int/en/country/cook-islands surveys improve data availability, but they would also increase conservation awareness and community responsibility. Surveys adapted from methods used in the Cook Islands Turtle Project conducted by Pacific Islands Conservation Initiative (Bradshaw & Bradshaw 2012); and/or those recommended by the Marine Turtle Specialist Group (MTSG) (Schroeder & Murphy 1999) could be used to assess annual abundance, distribution, and population. These could include beach surveys to evaluate the habitat and categorise its suitability for nesting (i.e., accessibility from open water, substrata type, sand depth, quantity of sand above high- water mark). All observed nests could be recorded with a GPS. Nests from where the hatchlings have departed can be excavated using standard MTSG guidelines (Miller 1999) to measure level of hatching success and confirm nesting species (if dead embryos are found). This type of community programme could be initiated and led by the local MMR officer based in Palmerston.

3.4 Crabs

Another key natural resource for Palmerston is the coconut crab (Birgus latro, unga), which is considered a delicacy by the people living there and throughout the Cook Islands. The crab is harvested for special occasions such as birthdays, community celebrations and when there are special visitors to the islands. In the past 12 months, the land crab Cardisoma carifex (tupa) has also been targeted commercially and sent to Rarotonga for sale.

Fig. 9. Coconut crabs play a key role in the ecosystem of islands, including helping to control the population of coconut trees.

Perhaps because it was not considered a ‘marine resource’, the coconut crab only received a passing mention as being “persistent in small numbers” and “collected in small numbers on some nights” in the marine resources survey which was carried out in 1988 (Preston et al. 1995: p.3, p.30). In 2009, the results of a household survey in Palmerston suggested that there had been a moderate decrease in population of coconut crabs since the 1990s (Pinca et al. 2009). No crab surveys were undertaken however.

In the 2018 R2R expedition to Palmerston, a coconut crab survey was undertaken by National Environment Service (Kora & Munro 2020). The survey indicated that the population status on Palmerston was reasonably healthy on four of the islets (Toms, Primrose, Bird and North), with Home and Cooks islets suffering from greater harvesting pressure due to their close proximity to the village.

The coconut crabs are currently being harvesting and sent to Rarotonga (pers comm A. Neale 2020). While the 2018 surveys showed a reasonably healthy status of the coconut crabs, such trading could easily result in the coconut crab population becoming over-exploited if not managed properly. Globally, they are listed as vulnerable on the IUCN redlist. Coconut crabs play a key role in the ecosystem of islands. Because of the risk of overexploitation, the following management recommendations are made.

3.4.1 Crab Management Recommendations

A number of management recommendations were made for coconut crabs by experts from SPC and NES, based on their 2018 survey and other regional experience (Kora & Munro 2020). Some of these recommendations are adapted for the purpose of this management plan and are provided below. A combination of several of these strategies may be required.

1. Island Council, with advice, to determine a minimum harvest size limit.

2. No female crabs to be harvested.

3. Conduct monitoring to determine if a breeding season exists and establish a closed season for collecting coconut crabs at that time. For example, on it is reported that adult coconut crabs spend several months in their burrows on the makatea, emerging for spawning in October or November (Clerk, 1981). The female carries the eggs under her abdomen attached to hairs. After about one month the female moves to the shore and releases the eggs into the sea. It is likely that a ban on taking coconut crabs from October until late December may have a very positive effect on the stock status.

4. Establish a continuous monitoring programme, using students from Lucky School.

5. Place a control on coconut crab exports, based on a sustainable harvest determined from the monitoring programme in point 4 above.

6. The Island Council select a suitable motu to act as a reserve for coconut crabs.

7. Proceed with a proposed rat eradication project (request from Palmerston Island Council to Te Ipukarea Society), removing a key non-native invasive species and competitor of the coconut crab. This will also assist in restoration of the motus into a more native state.

8. In addition, monitoring of the export of the tupa land crab should be initiated, to determine if management is required. A cautious approach would be to ban the taking of females carrying eggs.

3.5 Pa’ua (Giant Clams)

There are at least 2 species of pa’ua (Giant clam) in Palmerston; Tridacna maxima, and T. squamosa in much smaller densities (Preston et al. 1995, Pinca et al. 2009). A third local species has also recently been identified in the Cook Islands, T. noae (MMR undated). Though not recorded in Palmerston, this new species may well occur there having previously been assumed to be T. maxima.

Fig. 10: A small coral head with several pa’ua embedded into the coral. (Photo: Te Ipukarea Society)

Aitutaki had historically been the main source of pa’ua for the Rarotonga market. However, following a decline in stocks in Aitutaki since the 1980s, the main source of supply was transferred to Palmerston (Preston et al. 1995). This was also in response to a ban on exports from Aitutaki because of the overharvesting there. However, surveys conducted in 1988 by MMR and the South Pacific Commission indicated there were actually lower densities of T. maxima on Palmerston Island than on Aitutaki and some other Cook Islands, raising early concerns of over-exploitation on the Palmerston pa’ua resource (Preston et al. 1995). The Ministry of Marine Resources (MMR) more recently has analysed historical and more recent pa’ua data and have confirmed population declines and over harvesting (MMR, undated).

During the 2007 Procfish survey, researchers stated that shallow-reef habitat that is suitable for pa’ua was not very extensive at Palmerston (Pinca 2009), which may also explain the lower densities recorded in 1988. The 2007 survey also found the abundance of larger pa’ua was low, supporting the assumption that stocks are impacted by fishing. Despite an Island Council ban of commercial export of pa’ua from Palmerston in 2007, surveys conducted by MMR in 2018 identified that pa’ua stocks have not recovered, and represented less than one percent of all invertebrates recorded, with less than 2 clams per 100m2. The density remains lower even than in Aitutaki (Ainley & Morejohn 2019).

Based on advice from MMR, it was agreed by the local community in November 2018 during the R2R expedition presentations that the area behind Lucky School was to be ra’ui for pa’ua from 2018 until further notice. The ra’ui site is to be used as a monitoring site for local school students to monitor pa’ua densities based on the skills taught by the MMR R2R team from 2018.

Though the Cook Islands are not a party to the Convention on International Trade in Endangered Species (CITES), certificates required for their export to CITES member countries were previously provided by the Cook Islands National Environment Service (NES) on request. Permit records from 2008-19 indicate that 40 tonnes (mt) of pa’ua meat was exported from the Cook Islands within those 12 years. Following concerns raised by the Ministry of Marine Resources, as of July 2020 no more export permits are being given by NES, effectively stopping the export of pa’ua. Domestic exports and trade of pa’ua remains largely unregulated, except in islands where specific by-laws are in place, such as , Tongareva, and Aitutaki/Manuae.

3.5.1 Pa’ua Management Recommendations

Management recommendations from the 1988 survey included that exports be closely monitored, rotational closures of commercial harvesting be practiced and that size restrictions be considered by MMR and the Island Council (Preston et al. 1995). However, these recommendations were not implemented and the pa’ua population continued to decline. Advice and recommendations continue to be given by MMR, including in the most recent report from the 2018 survey and through ongoing communications.

Given the extremely low density of remaining pa’ua, it is recommended that a complete ban on harvesting be imposed until stocks recover to a predetermined density, e.g., 1988 levels.

In addition, it may be helpful to identify areas where pa’ua densities are higher and apply a complete ra’ui on all types of fishing activity in that area to minimise disruption to spawning activity. Once numbers increase to a pre-determined density, harvesting could begin with strict size limits and quantities set, for local consumption only.

A limited number of pa’ua could be relocated into groups to increase density and thereby improve the chances of successful spawning. Care should be taken to minimise any damage to corals during this process. In addition, approximately 50 brood stock could be taken from Palmerston to the Aitutaki clam hatchery. There they could be spawned, and juveniles returned to Palmerston for grow out. The logistics for such a trip would need to be closely considered, with as short a transit period as possible, and water quality maintained at a high level for the duration of the time in transit. However, the difficulties can be overcome, as has been demonstrated back in 1989 when several styrofoam containers of juvenile clams were successfully air freighted alive with minimal mortality from North Queensland to Aitutaki, via New Zealand and Rarotonga, on routine commercial flights (pers comm, K. Passfield, 2021). Alternatively, the Aitutaki hatchery manager could travel to Palmerston and assist in getting pa’ua to spawn successfully at a site where they have been aggregated.

Annual pa’ua monitoring surveys by students at Lucky School should be continued.

3.6 Tropical spiny lobsters

There are several species of tropical spiny lobsters (crayfish, koura tai) in the Cook Islands. The most common is Panulirus penicillatus, and this is caught in Palmerston around the reef rim by hand at night (Preston et al. 1995). During a 1988 survey, catch rates for lobsters averaged around 2 per hour, or just under 2kg (Passfield 1988). Based on this, as well as information from atolls in other parts of the Pacific, a yield of about 20kg per km of reef per year was estimated for Palmerston (Passfield 1988). There is however, no information available on the actual production or export quantities of lobster for Palmerston, nor any updated surveys on this species since the 1988 survey.

3.6.1 Tropical spiny lobsters management recommendations

Panulirus species have a long drifting larval stage of approximately 10 months (Matsuda et al., 2006). It is therefore likely that the lobsters that recruit to Palmerston’s reef actually come from other islands and countries in the region, unless localised current eddies return larvae to Palmerston to settle. Catching lobsters may therefore not impact further recruitment for Palmerston, though reefs further down-current from Palmerston may be affected.

A minimum size limit of 80mm carapace length was recommended in the Passfield (1988) lobster resource profile, and this remains a valid recommendation today. This allows lobsters time to grow to sexual maturity and spawn, as well as command a higher price on the market. A ban on taking females carrying eggs should also be put in place,

3.7 Trochus

An unknown number of Trochus (Tectus niloticus) were introduced to Palmerston from Aitutaki in the early 1960s, with a further 3000 introduced from Aitutaki in the 1980s (Passfield 1997).

A survey in 1988, however, found very few trochus present (Preston et al. 1995). Numbers increased after that time though and the first commercial harvest of trochus was undertaken nine years later in 1997, in which approximately 1.5 mt of shells were collected (Passfield 1997). However, the quality was reported to be very poor, with 70% of shells being badly worm-eaten and therefore of little commercial value.

Fig. 11.Trochus (Tectus niloticus) are now abundant on the reef in Rarotonga, but considered rare in Palmerston.

3.7.1 Trochus Management Recommendations

The current status of trochus in Palmerston is unknown, but none were recorded in recent surveys. The global price is not particularly attractive at present, so there is little incentive to consider a commercial harvest.

A survey of stocks should be undertaken to provide a baseline for future monitoring. If prices and stocks recover to the level where a harvest is economically viable, the same size limits that are imposed in Aitutaki should be established along with other management strategies. That is, only shells between 8 and 11 cm basal diameter should be harvested. Larger trochus have the capacity to produce many more eggs than smaller trochus, so it is best to leave these to act as brood stock. In addition, larger shells are often more worm damaged and therefore of lower economic value, reaffirming their use as brood stock. A survey of stock size should be done first, and only a harvest quota of 30% to 40% of the trochus stock between 8 and 11 cm should be set. This strategy has worked well in Aitutaki for almost 40 years and is accepted internationally as a good example of a well-managed fishery.

3.8 Sea Cucumbers Sea cucumbers (rori) are not known to be harvested for subsistence in Palmerston (Preston et al. 1995). A survey of sea cucumbers was conducted as a part of the 1988 Palmerston Marine Resource survey (Preston et al. 1995). Intensive searches of various places in the lagoon found only 3 common species; Holothuria atra, Stichopus chloronotus, and Bohadascia argus were present in low densities. None of these held significant value at that time. However, they are all are now commercially exploited in other parts of the world and bring in a reasonable return (Purcell et al. 2012).

The other common species found in the 1988 survey was Actinopyga mauritiana, or surf red fish, usually found on the reef crest close to the surf zone. It was harvested in the 1930s and exported to Tahiti, but no commercial export of this species has occurred since that time (Preston et al. 1995). The 1988 survey estimated a total stock of 14 mt of surf red fish, with estimations that 3 to 5mt was able to be harvested sustainably per year (Preston et al. 1995). However, there have been no reports of commercial export of any sea cucumbers from Palmerston in recent times.

Fig. 12. Red surf fish (rori puakatoro), while of medium value, was reported to be present in low densities. (Photo Te Ipukarea Society)

In the 2007 survey, Greenfish (Stichopus chloronotus) was recorded at very high densities and with widespread distribution (Pinca et al. 2009). This is now one of the higher value species, and could perhaps form the basis of a small commercial fishery. Surf red fish however were reported to have low densities in that same report. Holothuria atra and Stichopus chloronatus were reported as being common on the reefs in Palmerston in 2018 (Ainley and Morejohn, 2019)

Fig. 13. Greenfish, Stichopus chloronotus is a sea cucumber of medium commercial value. (Photo Te Ipukarea Society)

3.8.1 Sea cucumber management recommendations

Some limited harvest of several species of sea cucumbers could be possible in Palmerston. This may be one way to take some pressure off the parrotfish fishery yet still provide an income in the short term. There would need to be strict management, with a pre-harvest survey conducted and a quota of perhaps only 30% of the stock of each species harvested, within agreed size limits. Sea cucumber fisheries are very easily overexploited, so if a strict management regime were not able to be enforced, it would be best to leave the resource unfished completely, given the crucial role of sea cucumbers in maintaining a healthy balance within the reef system and lagoon (Purcell et al. 2016).

3.9 Birds

Palmerston acts as a layover site for migratory seabirds such as the wandering tattler (Tringa incana, kuriri), pacific golden plover (Pluvialis fulva, torea), ruddy turnstone (Arenaria interpres, parau’unga) and the bristle thighed curlew (Numenius tahitiensis, Teue), which is listed as ‘Vulnerable’ on the IUCN Red List and also listed in the Convention on Migratory Species (CMS) (Smith 2018). Palmerston also acts as a nesting site for other seabirds such as the red-tailed tropic bird (Phaethon rubricauda, tavake), brown booby (Sula leucogaster, kena), and red footed booby (Sula sula, toroa) (Smith 2018).

Fig. 14. A redtail tropic bird, Phaethon rubricauda, commonly known as a Bosun Bird in Palmerston. (Photo Te Ipukarea Society).

While the people of Palmerston harvest a number of seabirds for food, they are well known for their annual harvest of the red-tailed tropicbird, or bosun bird as it is locally called on Palmerston. The harvesting season typically runs from June till the end of August and cease each month when the quota of two birds per person per month is met (includes newborn to oldest resident) (Smith 2018). Crocombe (1987) said that that the quota can be one or two birds per person per month, presumably depending on the numbers of birds available. He also said that the original rule made by William Marsters was that no birds could be harvested after Christmas. Recently, anecdotal information suggests that not everyone abides by these rules (pers comm, J. Marsters, 2018). Attempts to get historical data on Red-tailed Tropicbird harvests have been unsuccessful to date.

Fig. 15. Sharing of the bosun bird harvest in 1988 (Photo Kelvin Passfield)

Other seabirds caught for food include the brown noddy (Anous stolidus, ngoio), brown and red-footed boobies, and frigate birds. The only land bird on Palmerston is the Pacific pigeon (Ducula pacific, rupe). These birds are also utilised as a food source. There are no set harvesting seasons for these birds, and they can be caught at any time of the year. A shotgun is typically used to hunt the rupe (pers comm A. Neale 2020).

Seagull eggs were reported to be harvested prior to 1926, however the birds never returned after a cyclone in that year (Crocombe, 1987). It is unclear what sort of birds these “seagulls” were, but they are unlikely to be the common seagulls found in New Zealand and Australia.

In the October 2018 R2R survey, Te Ipukarea Society’s field team observed 18 species of seabirds, of which 3 species were recorded to be nesting (Figure 3).

The red-tailed tropicbirds were found breeding on 7 of the 13 surveyed islets and had the highest number of breeding pairs counts of the three recorded nesting species. Primrose had the highest number of red-tailed tropicbird breeding pairs with 49, followed by Marion’s bank with 24 and Aaron’s point with 20. There were no signs of red-tailed tropicbird breeding pairs on Bird Island during the survey.

The red-footed booby was the second most commonly found breeding seabird during the 2018 survey. North Island had the highest recorded number of breeding pairs for the red-footed boobies with nine, followed by the small motu known as Lee To Us, with three breeding pairs. The brown booby was the only other breeding species found, with two observed on North Island and one on Tom’s Island. Figure 3 shows the results of the breeding survey.

Breeding pairs of species surveyed on Palmerston Atoll from the 27th to the 29th October 2018

Lee To Us Motu Ngangie North Island Marions Bank Home Island Aaron's Point Small Cooks Karakerake Tom's Island Primrose

0 10 20 30 40 50 60

Red Tailed Tropic Bird Brown Booby Red Footed Booby

Fig. 16. Total number of breeding pairs species surveyed on Palmerston Atoll from the 27th to the 29th October 2018

3.9.1 Bird Management Recommendations

Though several species of birds are consumed on Palmerston, the red-tailed tropicbird (bosun bird) is the species most sought after, and therefore the most likely to benefit from increased management. This bird is harvested every year over a three month season, with an organised harvest each month from June to August. Recently concerns have been raised over the harvest, as the third harvest of the year has not yielded as many birds as in previous years (pers comm A. Neale, 2020). However, without access to historical harvest records, it is difficult to provide appropriate management recommendations. A request on behalf of Te Ipukarea Society has been lodged in 2018 with the Palmerston Island Council to access the records, but they have still not been made available.

During the 2018 R2R survey, it was raised by local residents that the nesting season for the red-tailed tropicbird may now be occurring earlier in the year around March as opposed to May, the month before the start of the harvesting season. This is possibly a result of a changing climate. It may be impacting the harvests later in the year, as the birds typically leave the nest after 2 to 3 months (Schreiber and Schreiber, 2020).

In order to obtain additional information to supplement the annual harvest data recorded by the Island Council, it is recommended that a continuous monitoring programme for bosun nest counts be established, which could utilise students from Lucky School. The surveys should concentrate on the three islets that were found to have the highest bosun nest counts: Primrose, Marion’s bank, Aaron’s point. Surveys should start during the month of March to validate the assumption of a shift in the bosun bird nesting season. This would also better capture other nesting sea birds that may be nesting at this time.

Community safety concerns have also been raised around the use of shotguns to hunt the Pacific Pigeon. It is recommended that the matter be raised during the Palmerston Island Council meeting to determine whether the use of shotgun cartridges and firearms be banned from Palmerston Island. It should be ensured that all firearms registered with the police, which is a requirement under Cook Islands law.

A rat eradication project request was made to the R2R project, through Te Ipukarea Society, by the Palmerston Island Council in 2018. However, all funds had already been allocated. If an eradication programme were undertaken on islets where rats are found (Home and Cooks islet), this would further encourage seabirds to nest. Although rats have not been recorded as present on the remaining 11 uninhabited islets it would still be beneficial to conduct an intensive trapping survey on these islets to confirm this status thus ensuring the protection of seabirds from this invasive predator. The Executive Officer of Palmerston has indicated that they will try and fund an eradication in the near future through their allocated annual budget.

3.10 Trees

During the 2018 R2R expedition, Ministry of Agriculture (MoA) staff conducted surveys of the coconut resources on Palmerston. Some very important coconut varieties were identified, which are classed as very rare in the field of coconut research.

The first was spicata, which is two varieties on one tree, and multiple fruits on a single spikelet (Mataora 2018).

The second was a coconut with the qualities of a very good parent palm. These qualities included an average of 30 coconut per bunch, thin and easy husking, good size nuts, very sweet, very thick and tasty kernel (Mataora 2018).

Tamanu (Calopyllum inophyllum) trees are also an important resource for Palmerston, and some concern has been raised about their exploitation, for example for sending to Rarotonga for carving (pers comm A. Neale January 2021)

3.10.1 Tree management recommendations

The following recommendations were made by the MoA staff in their report.

1. Compile a full report of the work completed in Palmerston with the sample results and co-ordinates of selected parent palms for the Mayor and Executive Officer of Palmerston. 2. Design a coconut replanting model plan to improve the quality of for Palmerston using a combination of both traditional and scientific approach. 3. If rat eradication goes ahead on those islets where birds usually nest, consideration should be given to removing the coconut trees and replacing them with native trees such as Tamanu (Calophyllum inophyllum), and Kauariki (Terminalia catappa) which are more suitable for roosting and nesting birds. 4. Tamanu tree harvesting should be monitored. While selective trimming may be permitted, the removal of whole trees should be discouraged.

In addition, the area around these coconut trees should be kept clean, with old rotten trees removed, to reduce the possibility of infestation by termites.

3.11 Other species

There are of course numerous other species that are utilised in Palmerston. These include the green snail (Turbos setosus, ariri) as well as pelagic species of tuna, wahoo and mahi mahi, among others. However, there are no particularly significant interests in commercial harvest of any of these resources at present, nor are they known to be overharvested for subsistence. They have therefore not been considered at this time in the management recommendations of this report.

Under current law, the Cook Islands is a shark sanctuary, and it is illegal to catch or kill sharks. Sharks are not a target species, but it is possible that fishermen do kill sharks occasionally if they are taking the catch of the fishermen before the fish can be landed. No particular concern has been raised or noted however. Should this situation change in future, they can be included during a future review and revision of the Plan.

4. ADDITIONAL MANAGEMENT ISSUES

4.1 Visiting yachts and cruise ships

Visiting yachts can provide additional income to Palmerston through the sale of souvenirs as well as daily mooring fees. However, they can also bring biosecurity risks, as yachts could harbour invasive species such as rats and ants. They could possibly also have invasive marine life attached as marine fouling to their hulls. If yachts anchor on the reef, this can also significantly damage coral habitat, both from the anchor and the anchor chain that will drag over the bottom.

4.1.1 Management recommendations

1. More yachts could be encouraged to visit Palmerston as an added source of revenue to potentially replace lost revenue if parrotfish harvests were restricted. Yachts should always tie up to the moorings which are supplied for that purpose. No anchoring should be permitted. There are currently eight moorings positioned on the NW side of the island, and current costs vary from NZD$10-$20 per day. In addition to the mooring fees, there are also landing fees that supply further supplementary income for Palmerston. 2. There should be a quarantine inspection of the yacht before anyone from the boat goes ashore. Spraying of the boat with an insecticide and applying rat poison in the yacht before landing should be a requirement. ’s draft biosecurity plan could be used as a guide (Boudjelas et al. 2014). 3. No cleaning of the hull of the boat should be permitted within 12 miles of the island. 4. All waste discharge from visiting yachts should be prohibited within the lagoon and whilst tied up on the mooring. Plastic and non-biodegradable waste should be kept on board and disposed of at future ports that have facilities to deal with such rubbish.

4.2 Rat Eradication and biosecurity

The people of Palmerston have expressed interest in a rat eradication project for their atoll. The eradication of rats from Palmerston will contribute towards the Palmerston Management Plan through:

1. Increased biodiversity conservation value for seabirds, shorebirds, coconut crabs and sea turtles

2. Facilitating the return of a greater variety of seabird or migratory bird species to the island. 3. Improved agricultural crop success for local residents. 4. Using local residents to assist in the eradication project to encourage ownership of the follow-up biosecurity control required to keep rats and other invasives out. This would also reduce the costs and simplify logistics of such a project.

Fig. 17. Invasive rats can have a major impact on biodiversity. A rat eradication project is recommended for Palmerston. (Photo: Te Ipukarea Society)

The relatively small land area makes it feasible to assess rat presence on each motu through trapping and spreading the bait thoroughly on all motu containing rats. Overall, having a rat free atoll will result in Palmerston being more reflective of a naturally pristine environment, perhaps allowing for fuller restoration at a later time through facilitating greater success for native tree growth.

4.3 Biosecurity

A biosecurity plan, following the example of that prepared for Suwarrow (Boudjelas et al. 2014) should be developed in conjunction with the people of Palmerston. This will assist local residents in ensuring there are no re-infestations of rats, as well as guarding the atoll against other potentially disastrous invasive species such as red fire ants and others. This could include developing a short and easily understood training video on Palmerston’s biosecurity.

5. CONCLUSION

The people of Palmerston remain heavily dependent on their natural resources for food as well as for their livelihoods. Much of Palmerston’s harvesting pressure has been focused around their marine resources, in particular their parrotfish stocks. Commercial demands for these and other marine resources have risen from larger islands such as Rarotonga, particularly with the rise in tourism over the past decade. This management plan is an attempt to ensure these resources remain available to support the people of Palmerston well into the future. Some species specific and other more general management recommendations have been developed in this plan for further consideration by the people of Palmerston and key supporting stakeholders.

An important part of this plan is education and awareness. No plan will work if the community members are not convinced it is needed and are fully behind it. Therefore, before any of these management options are put in place, there needs to be comprehensive stakeholder consultation. This should include workshops on reasons for the proposed management recommendations, and discussions on the impacts on livelihoods and the alternatives that may be possible. For example, a complete ban on the use of gillnets would be the best option in terms of restoring healthy fish stocks and achieving ecological enhancement. However, unless alternative income sources were available, this would likely have a large impact on the livelihoods of the fishers, who rely heavily on this resource.

The role of the church in education and awareness is also very important. Church minister’s should undergo some environmental education as a part of their studies. They should be encouraged to use their position within the community to promote conservation and the benefits of applying management to help maintain the natural resources of Palmerston.

Whatever the agreed components of the management system that are put in place, it is important to ensure assessments of the impacts and responses are measured through streamlined data collection. Consideration should be given to the use of newly developed monitoring methods such as TAILS3 to further inform management and decision-making.

Routine ecological monitoring should also be supported through school projects around resources that have undergone previous monitoring training, such as those conducted in 2018 by NES, TIS and MMR. These included coconut crab surveys, red tail tropic bird surveys, pa’ua surveys, and how to look out for invasive ants.

In addition to the local monitoring, independent monitoring is recommended every five years to monitor sites and habitats that support high biodiversity, vulnerable species, predation, excessive fishing, alien species and invasive species. This could include establishing permanently marked sites, transects and quadrats for the reef, lagoon, beach and vegetation habitats.

This Palmerston Management Plan has been developed as a living document so it can be modified according to the results of future surveys and consultations, as well as with any changes in resource utilisation and other social and environmental changes over time. It is recommended that the plan is reviewed and revised as required, at least every five years.

3 Tails is a smartphone and tablet application that allows coastal fisheries staff to easily collect fish catch information from small-scale fishers in remote locations and send it instantly back to the main office for analysis, even when internet connectivity is limited. It is available from the Secretariat of the Pacific Community, through this link https://oceanfish.spc.int/en/ofpsection/data- management/spc-members/dd/505-tails-application 6. REFERENCES

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Ainley, L & Morejohn, K. 2019. Palmerston Nearshore Marine Assessment. Ministry of Marine Resources Cook Islands.

Balazs, G. H. 1995. Status of sea turtles in the central Pacific Ocean. Pp. 243-252. In: Bjorndal K (Ed). The Biology and Conservation of Sea Turtles (revised edition). Smithsonian Institution Press. Washington DC.

Boudjelas, S. R., Pierce, R & Cranwell, S. 2014. Biosecurity Action Plan for Suwarrow National Park. Unpublished draft

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7. APPENDICES

7.1. Appendix 1: Procfish Parrotfish fact sheet

7.2. Appendix 2: Preston et al. (1995) list of all finfish known from Palmerston