A field study was conducted to compare growth, feed utilization and nutrient excretions by feeding extruded pellet (EP) and moist pellet (MP). Slow growing flounder were used as the experimental animal to find out a prominent result in terms of growth and feed utilization. Weight gain of fish fed the experimental diets for 8 weeks reached 105.3 g for EP and 107.1 g for MP, while fresh feed intake was 98.7 g for EP and 279.4 g for MP. Feed conversion ratio was 0.94 and 2.61 for EP and MP, respectively which was 0.77 and 0.94 when corrected on dry matter basis. Even though protein efficiency ratio (2.26 vs 2.21), specific growth rate (0.69% vs 0.70%), daily weight gain (2.06 g vs 2.10 g) and mortality (4.0% vs 4.1%) were similar between EP and MP, protein retention efficiency of fish fed EP was superior (53.3%) to that of fish fed MP (39.6%). Protein intake of fish for 8 weeks was similar from 52.3 g for EP to 53.3 g for MP, while protein gain was higher in fish fed EP (27.9 g) than in fish fed MP (21.1 g). Protein excretion by feeding EP and MP reached 232 g and 300 g, respectively per kg gain, suggesting that protein loads could be greatly reduced in practical culture system through the use of EP. Phosphorus (P) intake was much lower in fish fed EP (1.63 g) than in fish fed MP (2.18 g), while retention of P was higher in fish fed EP (0.88 g) than in fish fed MP (0.78 g), showing the retention efficiency of 54.0% and 35.9%, respectively. Fish fed EP excreted 7.1 g of P per kg gain which was much lower than that of fish fed MP (13.1 g). The present results clearly showed that EP feeding for flounder is not only productive but also environmentally friendly.

2012년 12월, 한국 울산항 앞바다에서 항타선이 침몰되었다. 본 사고 선박의 침몰원인은 인적요소, 기상악화 등의 복합적인 문제라 여겨진다. 사고 이후 선박안전기술공단에서는 리더부(크레인)는 충분한 안전율이 확보된 강도로 설계되었다고 결론을 내렸으나 국립과학수사 연구원의 현장조사 감정서에서는 선박 침몰은 리더부의 파손으로 인한 것이라고 결론 내렸다. 이에 본 저자들은 선박안전기술공단이 선박 검사에 사용하는 선박안전법과 강도 계산 및 구조해석 방법 등을 검토하였다. 나아가 한국선급의 규칙을 기반으로 두어 선박 침몰원인을 분석 하기 위한 유체동역학적해석 및 구조해석에 관한 수치시뮬레이션을 수행하였으며 국립과학수사연구원의 현장조사 결과와 유사한 결론을 얻을 수 있었다. 결론적으로, 본 사고 선박과 같이 선급 규칙의 적용을 받지 않고도 자유롭게 국내에서 운항 될 수 있는 항타선의 경우 유사한 사고가 발생할 수 있으며 이를 방지하기 위하여 한국선급 규칙의 적용을 받는 검사가 수행되어야 할 것임을 제안한다.