これまで,相模湾沿岸域におけるアカウミガメ上陸産卵個体の減少原因については ,「道路 建設や侵食に伴う砂浜の消失」,「照明や騒音の激化による産卵可能な静かな砂浜環境の消失」あるいは「砂浜への自動車の乗り入れ(踏みつけ)」などが考えられてきたが,いずれも実例に基づく知見ではなかった.そのため,今回観察された袖ヶ浜(西)の浜崖基部の産卵巣流失は,「海岸侵食が相模湾沿岸砂浜域におけるアカウミガメ繁殖(孵化脱出1に対して甚大な影響を及ぼす」ことを示す数少ない記録である,KAMEZAKI et al.(2003)は,アカウミガメの個体数の減少原因として,海洋での漁業における混獲のほか,上陸産卵する砂浜の減少や侵食をあげている.
Until now, the causes of the reduced number of loggerhead turtle (Caretta caretta) individuals coming ashore to lay eggs in the coastal area of Sagami Bay have been thought to be, “the loss of sandy beaches due to erosion and road construction,” “the loss of quiet sandy beach environments where eggs can be laid as a result of an exacerbation in illumination and noise,” and “encroachment of sandy beaches by automobiles (trampling).” However, none of these are findings based on actual cases. Thus, on the topic of the washing away of nests at the base of the sea cliffs at Sodegahama (West), which we observed in this present study, Kamezaki et al. (2003), which is one of the few records indicating that “coastal erosion is severely affecting the reproduction (hatching and emergence) of the loggerhead turtle at the sandy beach areas along the coast of Sagami Bay,” cites bycatch by marine fishing operations and shrinkage and erosion of sandy beaches where turtles come ashore to lay eggs as reasons for the decline in the number of loggerhead turtle individuals.
Until nowTo date, the causes of the reduced number ofdecline in loggerhead turtle (Caretta caretta) individuals coming ashore to lay eggs inat the coastal area of Sagami Bay coast have been thought to be, “include the loss of sandy beaches due to erosion and road construction,” “, the loss of quiet sandy beach environments where eggs can be laid as a result of an exacerbation inelevated illumination and noise,”, and “encroachment ofon sandy beaches by automobiles (trampling).” However, none of these explanations are findings based on actual casesreal-world examples. Thus, on the topic of the washing away of nests at the base of the sea cliffs at Sodegahama (West), which we observed in this present study, Kamezaki et al. (2003), which is one of the few records indicating that “coastal erosion is severely affecting the reproduction (hatching and emergence) of the loggerhead turtle at the sandy beach areas along the coast of Sagami Bay,” cites bycatch by marine fishing operations andas well as shrinkage and erosion of sandy beaches where turtles come ashore to lay eggs as reasons for the decline in thedeclining number of loggerhead turtle individuals.
Theo date, the causes of the decline in the numbers of loggerhead turtles (Caretta caretta) individuals that comeing ashore to lay eggs onat the Sagami Bay coast have been thought to include the loss of sandy beaches due to erosion and road construction, the loss of quiet sandy beach environments where eggs can be laid as a result ofdue to elevated illumination and noise, and encroachment on sandy beaches by automobiles (trampling). However, none of therese explanations are no studies that confirm these causesfindings based on real-world examples. Thus, on the topic of theIn this study, we observed loggerhead turtle nests at the base of the sea cliffs at Sodegahama (West) being washeding away of nests at the base of the sea cliffs at Sodegahama (West), which we observed in this present study,. Kamezaki et al. (2003), one of the few records indicating reported that “coastal erosion is severely affecting the reproduction (hatching and emergence) of the loggerhead turtle at sandy beach areas along the coast of Sagami Bay,.” They citeds bycatch by marine fishing operations as well as the shrinkage and erosion of sandy beaches where turtles come ashore to lay eggs as reasons for the declining numbers of loggerhead turtle individuals.
To date, the cCauses of the decline in the number of loggerhead turtles (Caretta caretta) individuals that comeing ashore to lay eggs onat the Sagami Bay coast have been thought to include the loss of sandy beaches due to erosion, and road construction, and encroachment by automobiles (trampling) and the the loss of quiet sandy beach environments where eggs can be laid as a result ofdue to elevated illumination and noise. , and encroachment on sandy beaches by automobiles (trampling).” However, none of therese explanations are no studies that confirm these causesfindings based on real-world examples. Thus, on the topic of theThus, in this study, we observed the washing away of loggerhead turtle nests at the base of the sea cliffs at Sodegahama (West)washing away of nests at the base of the sea cliffs at Sodegahama (West), which we observed in this present study,. Regarding the washing away of loggerhead turtle nests, Kamezaki et al. (2003), one of the few records indicating reported that “coastal erosion is severely affecting the reproduction (hatching and emergence) of the loggerhead turtle at sandy beach areas along the coast of Sagami Bay,.” They citeds bycatch andby marine fishing operations as well as the shrinkage and erosion of sandy beaches where turtles come ashore to lay eggs as reasons for the declining number of loggerhead turtle individuals.