Hawaiian, Islands (Kikuchi, 1976

Wild-harvest of Hawaiian seaweeds

Gathering seaweeds in the Hawaiian Islands is not just about collecting a food source, but is also a way for people to “connect with place,” and to observe details about the seaweeds’ growth, reproduction, and seasonality ( Hart 2012). The connection that seaweed collecting creates among people is cherished: “Whole families from grandparents to their small grandchildren are often seen at favored limu places, gathering a variety of edible seaweeds, exchanging greetings and recipes with others, and enjoying a day in the sunshine” ( Abbott 1978, p. 410). In 1976, approximately 36,000 kg of fresh limu were gathered by families for their own use; another 36,000 kg fresh weight of two species of wild Gracilaria , and 11,340 kg fresh weight of other Hawaiian seaweed species were sold in markets ( Abbott 1978). A variety of wild-harvested seaweeds were once common in local markets, but species availability has diminished. At least eight wild-harvested species were sold in 1976; four species were available in 1985; only two are found in 2018 with significant price increases ( Table 2). Probably the most favored and expensive ( Abbott 1999) species available for purchase is Asparagopsis taxiformis (limu kohu), which currently sells for US $25.00–27.00 lb−1 fresh weight (= US $55–60 kg−1). In 1986, the State Division of Aquatic Resources (DAR) began recording the annual harvest of three species of seaweeds and the number of permits issued for the collection of A. taxiformis and Codium spp. ( Figure 6). “Wild catch” and the number of collecting permits have fluctuated wildly during the last 30 years, but show a general decline in recent years. Cultivation of native and introduced species of Gracilaria has attempted to fill the void caused by lack of wild-harvested seaweeds.

The first and only report of seaweed toxicity in the Hawaiian Islands was made in 1994, when people consumed wild-harvested Gracilaria coronopifolia from Maui in early September and experienced burning sensations in the mouth and throat and/or serious gastrointestinal illness ( Marshall and Vogt 1998). Assays of the seaweed from the picnic and from the original harvest site contained debromoaplysiatoxin and aplysiatoxin, two toxins known to be produced by the cyanobacterium, Lyngbya majuscula Harvey ex Gomont ( Moore 1981) . Marshall and Vogt (1998) concluded that the

Wild Seaweed Catch

9000

8000

7000

25

20

6000) kg (weight 5000 Wet 4000

3000

2000

1000 15 permits of 10 Number

5

0 limu kohu limu wawae ‘iole limu kohu permits limu wawae ‘iole permits limu manauea + ogo

toxins possibly came from the blue-green epiphytes they observed on the G. coronopifolia samples!