1. Tourism in marine environments is growing each year, especially in regions with attractive coastlines. One of the main activities practised by tourists is offering food, normally bread, to fish. This activity can result in negative impacts that are still not fully understood. Such impacts were previously detected among omnivores, but fish at other trophic levels also respond to feeding by humans.
2. The effects of supplementary fish feeding by tourists on the diet of a coral reef predatorial haemulid fish, a common reef fish in many tourist destinations, were analysed. Specimens were sampled from one location in which tourists frequently feed the fish and another in which fish maintain their natural diet, both in a marine protected area. The standard length, total weight, hepatosomatic index, condition factor, starch content, and diet composition of fish from the two locations were compared.
3. Specimens fed by tourists were generally larger than those consuming a natural diet, but weight, hepatosomatic index, and condition factor were not statistically different. Diet composition varied between the two areas, with almost half of the stomach contents from specimens collected in the supplementary feeding area composed of starch. Considering the natural diet of this species, carbohydrate ingestion can interfere with energy accumulation. Additionally, natural prey species were being consumed on a smaller scale.
4. These results shed light on the controversial issue of supplementary fish feeding as a tourist attraction and provide information to help shape effective ecotourism management. In this regard, the offered food volume should be banned in more sensitive environments, reduced in remaining areas and food quality should be controlled to make ecotourism a more sustainable activity globally.

中文翻译：

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将鱼作为旅游胜地喂食对珊瑚礁自噬鱼的饮食和生长的影响

1. 海洋环境中的旅游业每年都在增长，特别是在海岸线迷人的地区。游客从事的主要活动之一是提供食物（通常是面包）给鱼。此活动可能会导致负面影响，但尚未完全了解。以前在杂食动物中检测到这种影响，但其他营养级别的鱼也对人类的摄食作出反应。
2. 分析了游客补充喂鱼对珊瑚礁掠食性haemulid鱼（在许多旅游胜地常见的礁石鱼）饮食的影响。在一个海洋保护区，从一个游客经常喂鱼的地方和另一个鱼保持自然饮食的地方取样。比较了两个地点的鱼的标准长度，总重量，肝体指数，条件因子，淀粉含量和日粮组成。
3. 旅客喂养的标本通常比食用天然饮食的标本要大，但体重，肝体指数和条件因子在统计学上没有差异。饮食组成在这两个区域之间有所不同，从补充饲喂区域收集的标本中，几乎一半的胃内容物由淀粉组成。考虑到该物种的自然饮食，碳水化合物的摄入会干扰能量的积累。另外，天然猎物物种的消费规模较小。
4. 这些结果阐明了有争议的补充鱼饲料作为旅游胜地的问题，并提供了有助于制定有效生态旅游管理的信息。在这方面，应在更敏感的环境中禁止提供的食物量，减少剩余区域，并应控制食物质量，以使生态旅游成为全球范围内更具可持续性的活动。