The 18th Century Sea Fortress of Ruotsinsalmi, Kotkansaari in Finland: Archaeobotanical Data of a Log Latrine

In archaeobotany, plant remains from latrines have been used to derive information on historical food consumption. In this interdisciplinary paper, we present new archaeological and archaeobotanical data from the 1790s sea fortress of Ruotsinsalmi in Kotkansaari, Finland. Archaeological research revealed the remains of an infantry barracks and a well-preserved log latrine at the sea fortress. The contents of the latrine were excavated, and waterlogged human faeces were found. To reconstruct the food consumption of the soldiers at the sea fortress, we carried out archaeobotanical analyses on the faeces. The waterlogged human faeces consisted purely of plant remains and fish bone fragments. The analysis of the plant remains gave records of 77 different plant taxa, and common millet (Panicum miliaceum L.) and sage (Salvia officinalis L.) were identified for the first time from archaeological layers in Finland. The remarkable number of cultivated and exotic plants recorded from the faeces shows that imported as well as locally produced food was used. Latrines offer evidence of consumed food in the past Latrines are a type of primitive toilet that collects human faeces, and the word latrine originates from Latin 'latrina' or 'lavatrina' meaning 'to wash'. Latrines provide excellent preservation conditions, and therefore the content consists of a range of biological materials such as seeds, fruits and plant tissue. Latrines are historically also used as waste pits, where the household rubbish and sometimes even animal dung was thrown. Therefore, archaeological latrines are an excellent source of information on the past diet and waste disposal, and they also provide information about the natural surroundings of the latrine (Markle 2005, 427; Smith 2013, 526). Macrofossil, pollen, and zoological analyses of latrines have been conducted e.g. in Turkey (Baeten et al. 2012), England (Moffet 1992; Smith 2013), Germany (Wiethold 1995; Markle 2005), and Denmark (Andersen & Moltsen 2007). From Estonia over 30 latrines have been excavated (Bernotas 2008). Latrines have been excavated in Finland as well, from the medieval (AD 13th-16th c.) layers of Turku (Sartes & Lehtonen 2007; Seppanen 2012). However, no botanical analyses of these latrines have been carried out. Therefore, there has been little direct evidence of the diet. What cereals were eaten? Were exotic fruits parts of the diet? [FIGURE 1 OMITTED] The sea fortress of Ruotsinsalmi (1790-1855) in Kotkansaari was the predecessor of the present town of Kotka (1878-, Fig. 1). During the past ten years, some twenty archaeological studies have been conducted on the Island of Kotkansaari (Kykyri 2013a, 60; 2015, 38 f.). These investigations have shed new light on the history of the island, but so far only limited knowledge has been acquired concerning everyday life at the sea fortress. New information was gained when the Museum of Kymenlaakso carried out excavations at the sea fortress in the summer of 2013. During the excavations a log latrine containing waterlogged human faeces was discovered (Kykyri 2014a; Kykyri & Lempiainen-Avci 2014). These faeces were archaeobotanically analysed in order to find evidence of past human diet, and to gain detailed knowledge about the food consumed at the sea fortress. In this paper, we present new archaeological and archaeobotanical data from the sea fortress of Ruotsinsalmi in Kotkansaari, in addition to discussing the usage and origin of the plants which yielded archaeobotanical remains. The history of the fortress The sea fortress of Ruotsinsalmi was built in the 1790s on the Island of Kotkansaari and some smaller surrounding islands, by order of Empress Catherine the Great. The Gustavian war (1788-1790) between Sweden and Russia had shown that Russian defenses in south-eastern Finland were in need of prompt strengthening. In order to ensure the defense of St. …