Post 360 ± 40 BP (cal AD 1440-1640), fish remains disappeared and salt residues declined significantly (Table 1). These events coincided with the appearance of Dutch smoking pipes (Table 1), signalling the arrival of Europeans. It is known that England, France, Denmark and Sweden exported Dutch pipes to West Africa during the 17th and 19th centuries (Walker 1975). The pipes recovered from Ahanve have no marks or inscriptions but have a 'milled rim' feature on their surface and a 'delicate cog-wheel-like denticulation round the bowl rim' (Walker 1975, 185) (Figure 6). These are characteristic features of Dutch smoking pipes. In addition, the Dutch established a trading post in Apa prior to 1734 until 1736, when it was moved to Badagry by Hendrick Hertog for economic reasons (Alabi 1998). The proximity of Ahanve to Apa accounts for the occurrence of Dutch pipes in Ahanve. Europeans have visited the West African coast since the 15th century (DeCorse 2001). Initially, the focus of their attention was on the western side of the region. Their presence in Nigeria became prominent in the 16-17th centuries. Ahanve traditions indicated that during the transatlantic slave trade there were restrictions, particularly on fishing expeditions and transportation on the water-ways (Chief Suru Toyon, pers. comm. 2008). Persons who violated these restrictions ran the risk of being captured and sold as slaves. Although these alone do not satisfactorily explain the non-recovery of fish remains from the excavated unit, what is clear is that consumption of fish declined drastically in Phase II. Palynological evidence from the topmost levels (0-20cm) of the sediment core indicated that during this phase there was abundant pollen of weeds and plants associated with agriculture, and human disturbances of vegetation, as well as microscopic charcoal (Orijemie 2013). The pattern of increase in microscopic charcoal indicated that the fires were continuous and regular in occurrence, features consistent with anthropogenic fires. In addition, the marked increase in the pollen of weeds and plants associated with human habitation and cultivated areas indicate that there was increased reliance on plant-based resources. Another possibility is increased human population, but there is as yet no demographic evidence of Ahanve during this period. The recovery of bivalves below 80cm depth in the excavated unit but not above indicated continuous usage up until that point. Ahanve, and indeed the BCA, was terrorised by mainly Ijebu slave raiders, who ravaged the area during the trans-Atlantic slavery period. These raids led to Ahanve being internally displaced at some point. The scarcity of finds such as pottery and charcoal, and absence of palm kernels between 80cm and 50cm depth are indications Ahanve was either sparsely populated or abandoned at those times. In addition, pressures from slaving activities and the trauma of being subsumed under foreign authorities led to disruption of the socio-political lives of the people. The disruption was severe to the extent that Dahomean soldiers were able to raid the BCA between the 18th and 19th centuries without any resistance as they destroyed towns and took people to be sold into slavery. The European colonists did little to prevent these raids, which supported their own need for a source of slaves. Old Oyo, under whose protection the BCA had been, could not help because it had been consumed by a combination of Hausa-Fulani forces and traitor chiefs (Morgan 1971).
The decrease in the occurrence of salt residues is an indication that salt production was probably discontinued. Considering the importance of salt, indigenous production would have been discouraged particularly where a cheaper and less laborious alternative existed. Oral traditions stated that an embargo was placed on indigenous salt production to allow for massive importation of European salt. Consequently, imported salt took precedence over locally made products as it does today. Due to the abandonment of salt production, this aspect of the people's material culture is almost lost as the trade is rarely practised today. In fact, only a very few elderly persons can replicate the indigenous salt production technique.
The saltwater fern, Acrostichum aureum, is regarded as a highly medicinal plant in Ahanve. The roots are considered poisonous, hence are not consumed. However, concoctions from the roots are used as ointment for newborn babies. Acrostichum aureum is also used by the people to treat skin infections and severe stomach ache. The analgesic and anti-inflammatory properties of Acrostichum aureum have been confirmed by Khan et al. (2013) and Hossain et al. (2011) respectively. It is remarkable that the people recognised the medicinal values of this fern, a relict of the once-diverse mangrove swamp forest.
A variety of brooms and mats are common in Ahanve today. They are manufactured from the stems (straw) of Typha australis and T. domingensis. Stems of these aquatic plants are harvested and dried. For brooms, the strands are bound together at one end and used for sweeping. Straw is skilfully woven to produce mats. Those made from T. australis are preferred because the strands are finer, slimmer and are considered to be more beautiful and pleasing to the eye. In addition, T. domingensis retains moisture; the mats produced with it are thus less durable. The ethnobotanical uses of aquatic plants enumerated above such as Acrostichum aureum, Typha australis and T. domingensis still continue. It is probable that ancient Ahanve people used these plants, i.e. Typha and Acrostichum, for similar purposes in the past as they do today.