| 581 | IIA1 | 1968 | 28 |
| American Society of Ichtyologists and Herpetologists – člen. | |
| 582 | IIA1 | 1969–1985 | 28 |
| European Ichtyological Union – člen. | |
| 583 | IIA1 | 1982–1990 | 28 |
| European Inland Fisheries Advisory Commision (EIFAC pri FAO) – člen working group on Introductions. | |
| 584 | IIA1 | 1992 | 29 |
| East European Enviromental Research (ISTER) – člen ? | |
| 585 | IIA1 | 1968–1997 | 29 |
| Food and Agriculture Organization of the United Nations – rybársky konzultant. | |
| 586 | IIA1 | 1970–1999 | 30 |
| National Geographic Society, USA – člen. | |
| 586a | IIA1 | 1997 | 30 |
| New York Academy of Sciences – člen. | |
| 587 | IIA1 | 1999 | 30 |
| Ramsar Convencion (UNESCO) – expert. | |
| 588 | IIA1 | 1990–1997 | 30 |
| Scientific Committee on Problems of the Enviroment –Slovenský národný komitét – člen. | |
| 589 | IIA1 | 1992–2002 | 30 |
| Societas Internationalis Limnologiae (SIL) – člen; Societas Internationalis Limnologiae Theoreticae et Aplicatae (SIL–IVL) | |
| 590 | IIA1 | 1974–1993 | 30 |
| Man and the Biosphere (MAB UNESCO) | |
